I have added the instructions and suggestions here if that link did not work for you."Evaluate the condition on how rusty or bad is this piece. Soap and water with a wire brush may be all that is needed. What to look for when inspecting; amount of rust, crustacean of oxidized metal, heavy carbon build-up, burns and pitting. Before starting, I wash the item in plain luke warm soapy water normally from a 5 gallon plastic bucket out doors or in the garage as the kitchen in the home is off limits to this out door cook.If the rust comes off easily with some cleaning from the wire brush, I don't need to add any other chemicals nor use any special tools. However if there is heavy build up of carbons and or deep rust, I will either soak in vinegar mixed or go straight to using and electric drill with a wire brush attachment. I prefer to normally soak an item first after washing. Since warm soapy water will not be enough to break down the corrosion I rinse and discard the soapy water replacing with vinegar and water mixed. This is to make the job easier to perform and different methods can come into play.The electric drill with the wire brush attachment may be needed. However, it is more work than using a soaking solution plus as the non toxic chemical works away the rusty surface, it makes it simple to clean and finish.The cheapest and safest chemical is soaking in white vinegar. While it can be used as is, I dilute it 50/50 for heavily corroded surfaces. If it in minor rust which is not but in some spots, I will dilute 1 part vinegar to 10 parts water. However, for serious restoring, 50/50 (one to one) is the way to go for a heavy job.I like using a 5 gallon capacity plastic bucket. Fill (1 gallon vinegar with 1 gallon water) into the bucket, then place the cookware item in completely covered by the solution. For griddles or extremely large pieces, a plastic wash tub may be needed in order to completely cover the piece under the solution.Allow the item to soak until the rust is gone or easily moved off with the wire brush. Since vinegar can have a mild odor, I recommend doing this outdoors. Check on the item periodically and remove the piece from the vinegar bath as soon as the rust is gone or easily removable. This will depend on the level of rust and may take anywhere from a few hours to soaking overnight. Scrub using a wool pad in small areas under handle or rim and dip back into the solution as you clean. Once finish, rinse and then wash in warm soapy water again. CHEMICALS: Rust Remover Toxic ChemicalsOthers will suggest using Coke Cola as it too has an acid level along with using a lye solution. That is up to you should you decide too. Do they work better? Not really but they do work. If deciding to use a lye solution, you should include rubber gloves and goggles as it is a hazardous chemical that will cause skin burns and avoid getting into your eyes. Vinegar being less harmful works and if I need to revert to more extreme measures to remove rust, there is always the electric drill with the wire brush attachment. Although, some will use and swear by harmful chemicals such as Navy Jelly, Oven Cleaners, Lye, Lime Away, or commercial industrial cleaners like Boeshield, Bull Frog, Evapo-Rust or Gempler's. Yes they remove rust, but they are toxic and even after thorough washing, a ever slight film of toxic remains which when heated can mix into foods. Why pressure yourself with harmful risk taking chemicals if you can just avoid this by not using them. If the Hazardous material list on the product indicates it is harmful, it is. So use vinegar. Vinegar does the same job except rather than in 15 second, 15 minutes, it might take 15 hours but does not leave a toxic application after being washed.Although, if I was getting ready to paint a piece of metal like outdoor furniture, I'd might use it since I am not cooking on it. These chemicals have a place but not on cookware. Why worry about micro traces of harmful chemicals? They can leave traces of toxins that can be fatal. In an age of healthy living, use what you know is safe. ELECTROLYSIS:You can elect to use electrolysis which works very good in aiding to remove the rust. Electrolysis will make it look nearly new bathing from one day to several days in chemically charge solutions using a battery or other form of electricity. Professionals do this often but you need to have the equipment and skill and some practice working with electrolysis because while it works great. It can also be set up for under fifty bucks, but if you do not know what your doing, you can also begin eating the cast iron away doing this wrong. It's a great method for those who have the skill while being fairly inexpensive doing it yourself. SAND BLASTING:Sand blasting will also turn your piece into looking brand new. It works well, cost much more unless you have a friend who is in the auto-body repair shop or industrial paint shop business. Sand blasting strips everything to bare metal requiring only to reseason the cast iron. However, since most can do this task cheaper, why expend more than the cost of replacement of the item. It is not cheap paying someone to do this. POWER TOOLS:Grinding tools: If the piece is so heavily rusty that simple cleaning will not do the job easily, this is the next best thing. It is using a hand drill, wire wheel, or rotating wire brush. Some of my friends ask, why don't I just go straight to using this first since it does a great job removing all the unwanted rust and restoring the piece to bare metal: Well, it is simple but not as safe requiring eye protection, gloves for hand protection and the place to operate the drill, normally outdoors, the garage, basement or barn since the wife continues to rule the not working in the kitchen policy. . When using the hand drill, I also use a dust respirator or tie my bandanna around by face to prevent breathing micro particles that could be harmful.The hand drill does leave sometimes a larger mess and takes a little more work but it is affordable. A Dremel tool could be used but I prefer the hand drill as it is able to perform a heavy duty job. Using the electric wire brush, allows you to remove the surface rust easily. Some folks will even use a propane hand torch to heat the surface which can help remove that unwanted rust. Is it necessary to do so? Not really. So I don't mess with that process. BEST METHOD:The method which is the safest, most affordable with the least effort of elbow grease is best. Working smarter, not harder. While many select different methods, I went with this Old School method used by my grandmother and then my mom as it takes little effort getting your cast iron looking new again. Here's our step by step how I restored the above BEAN POT, but this works with all cast iron cookware.First: Wash in lukewarm water. After the wash, I took my hand steel brush to the lid and found the rust would easily remove with some elbow grease. I brush all the surfaces and found that it was getting more difficult removing some areas. After Soaking Cleans EasilySecond: Taking my 5 gallon plastic bucket, I filled (1) gallon of white vinegar to (1) gallon of water and allowed both the pot and lid to sit for one hour. I came back and the rust easily was removed using the wire brush without the need of using my drill. I scrubbed all the rusty surface clean.Third: Wash and rinse; thoroughly in warm soapy water. The soapy water neutralizes the vinegar acid.Forth: Wiped dry with a towel and place in the pre-heated oven at 250 degree (F). This temperature is used to dry the cast iron.Plus it allows the cast iron to preheat while drying. Always slowly heatcast iron cookware. Dry in oven before SeasoningFifth: Wearing a pair of leather gloves, I remove one piece as this has a lid. Placed on a cookie sheet, I rub it down with a thin coat of lard or shortening. This is the seasoning process that protects the cast iron from oxidizing and prevents acidity in cooking some dishes to effect the cast iron plus on skillets creates the carbon bonds needed to make a non-stick surface.Cover the entire area inside and out, I place the item aside and removed the lid from the oven repeating this wiping down with lard process top and bottom. I once again, place both items into the oven, increasing the temperature to 500 degrees (F) and allow it to sit for one hour.Sixth: I remove the items from the oven inspecting for any missed rust, coating and appearance. It looked good requiring no further work cleaning or seasoning. I placed back into oven with one light coat rubbed very thin and turned the oven off. I allowed it to cool overnight until the cookware returned to room temperature. When you remove your cast iron cookware, it should left with a dry, smooth non stick surface. If it is sticky, you may not have had it in the oven long enough or hot enough. Read Seasoning your Cast Iron Cookware concerning questions about seasoning. Finished restored CAST IRONOver time, rust may reappear. If this should occur, simply mix a tablespoon of oil to a teaspoon of salt and scrub the area with a paper towel. The salt works like an abrasive. The oil recoats the area oxidizing.Note: As the oily surface heats, the coating creates a sealant on the metal surface. This oil can also burn creating smoke. A fan above the oven should be used or use the outdoor grill with enough coals to allow the temperature to achieve 500 degree (F).Tools needed: 1 gal white vinegar1 five gal plastic bucket1 hand wire brush1 cloth towel1 steel wool pad1 can Crisco Shortening1 pair rubber gloves1 pair leather protective gloves or pot holders1 electric drill with wire brush attachment if needed"It is important for you to click the stars after you have read this answer.