Hello, and welcome to Justanswer. My name is XXXXX XXXXX I will be helping you today. If you need clarification on something please post back here.
First here are two pictures for reference.
There are a total of 4 bolts and 1 nut securing the lower unit to the midsection, 2 on each side, and 1 up front. It sounds like you got those, but you still need to disconnect the shift shaft.
In the picture locate items numbered;
29 through 34, and number 36.
That is everything that makes up the shift rod. The shift rod exits the lower unit towards the front of the unit. It travels the length of the midsection, and comes up through the top just under where the carb is in the engine.
Part 36 is the shift rod
Parts 29 and 32 are the little pin and clip that you need to remove to free up the rod.
When you look at the engine it is hiding there under and in from where the carb is.
On most of these small engines you have to remove the carb to have access to the pin. Sometimes you can get them out if you have long needle nose pliers, but when you go to put it back together it is harder if the carb is in the way, especially if you drop the pin and you have to fish it out. I won't lie, it is tight to access it and kind of a pain to get to, but it can be done.
After you get the shift rod disconnected the leg will drop right down, barring any corrosion holding it in place.
If this answers your question please hit accept now. I am still here afterwords for any and all follow up questions. Good luck and Happy New Years!
On either side of the gearcase is the water inlet screen. There are two phillips head screws on either side. Remove the screws.
Remove the inlet screens.
You will see inside the cavity a coupler. Disconnect the coupler with two open end 1/2" wrenches. Hold the bottom shaft nut and turn the upper nut. Once disconnected pull the upper nut up the shaft to expose the small plastic keeper. Note the direction it is put on the shaft.
Using a small screwdriver find the split in the keeper and carefully pry it off the shaft.
With the keeper off you can now pull the upper coupler nut off the shaft and remove the gearcase.
Note you may have to "chip" some paint off the shaft.
If you do not release the coupler the lower unit can not be removed, and you will severely damage parts forcing it.
Installation is the reverse of removal.
Put a tiny dab of grease on the threads of the coupler.
Yje screens are number 30 the couplers #66 and 49 and the keeper #73