If I would have swapped seat bottoms my co-pilot would have given me 10 lbs. of s--- about it.
My seat bottom came out after removing 4 bolts. The leather fabric is sewn to plastic "J" hook which hooks over the edge of the frame. It is a little *****y getting it free. I then cut a piece of ridgid foam to fit the bottom assembly, also a piece of heavy carpeting the same size. I put the new foam against the bottom of the old foam and the carpet against that and then put it back onto the springs/frame. Rehooked the leather fabric j hooks and bolted it back in. I did put a layer of foam on the left side under the leather to kind of build that back up a little. The whole idea of the carpeting is to keep the foam from being cut by the springs when you put your butt on it.
All in all it came out pretty good. A lot more comfortable and the back now hits me in the correct place to do some good.