It was a pretty straight-forward job. There are a couple of little things I discovered:
-I used a jigsaw to cut the Styrofoam seat. When you're cutting the seat back, the saw foot needs to be angled to compensate for the angle of the seat back so you get a nice cut. I didn't do this, and had to fill in with foam shims and construction adhesive.
-That same angled seat back, when in place, will rise up if you lean on it (when it's in the boat). I used those carpeted wooden blocks to keep it from moving.
-I found that the seat base I made wanted to slide around on the carpet. I screwed a couple of blocks on the front corners that wedge it in place. The wedges aren't visible once the base is in position on the boat.
Those are the big things I remember. The rest of it is just taking your time and thinking about what you want it to look like.