Hello! First tool you will want to acquire is a very sharp, 90° pick. You will need this for removing trim. You will also need a 10mm socket with extension.
First, remove the "shark fin". Its the triangle shaped trim piece, directly behind the outside mirror. It has three clips, two that snap into the door frame and one that snaps into the door panel. Use your pick to get behind the shark fin and pull it away from the door so you can get your finger behind it and it will pop off. You may need an additional screwdriver to help you pop it off the door panel (to prevent damage).
Then, you will need to remove the trim piece that is behind the inside release handle. If you pull on the handleyou will see the trim has a little notch at the bottom. Use the pick to go in the notch and push up as you pull out. The notch gives you access to the retainer tab at the bottom of the trim and by pushing or prying upwards it helps release that retainer and of course to pull out disengages it. It takes a little "finesse", it may not come right out. There are also two retainers on the top of the trim, you just have to shake and pull to release them, there isn't a way to manually release them. This will expose a 10mm bolt which needs to be removed.
Then go to your lock handle. With it in the "unlock" position, you will notice a square towards the bottom. This square needs to come out. If your pick is sharp, it will help. Use the pick to get under the square and pry it out, then slide the lock handle straight up off the lock rod. GM wants you to replace that square each time its removed because it usually gets damaged, but I've learned with a sharp pick, you can remove it without damaging it.
Pry up on the window switches to pop the switch assembly out. There are no hidden screws, it will pop right out. Then unplug all the wires.
Next, behind the inside pull handle (the large handle you pull the door closed with), there is a plastic trim piece. Use the pick to get behind the trim and pop it out (comes out very easy). This will expose the last two 10mm bolts. Remove them.
Now the panel is ready for removal. Starting in the upper front corner (where the shark fin was located), use your fingers to get behind the door panel and begin to pull it away from the door frame. There are multiple plastic retainers, and you kinda have to use a "jerking" motion to disenage them. Don't try and yank the whole panel off at once, start in the upper corner and work your way around. There will be a few retainers that are real hard to get out, just go little by little till you make it around to the other side.
During the removal process, you may notice some black plastic retainers may fall to the ground, don't worry about them, you can throw them away. They were used at the factory to retain the water barrier to the door panel. ONce installed, the water barrier is glued to the door frame and no longer needs to be attached to the door panel, so this causes the black retainers to pop out. Throw them away.
Also, the top of the door panel has a lip, that engages to the inner window seal. Once the door panel is disengaged from the door frame, just lift up an inch or two to unseat it from the window seal, BUT DON'T MOVE IT FAR!!! There is a cable attached to the inside door handle, that will break if you pull the door panel too far away without unhooking the cable. You need to pull the panel as far away as it will go so you can access the cable. Where it goes into the door handle, there are two little tabs. Use your pick to depress those tabs, so you can pull the cable out.
Thats it! PLEASE let me know if one of these steps is not clear or you need further assistance!