In the following pict you will see where I cut out the transom boxes and removed the last two feet of inner liner to redo my transom. The "back rest" part of those box seats were glued to the transom with thickened resin. There was also alot of thickened resin on the top edge of the transom. I had to cut the side edges of the transom and use long chisels and pry bars to break that thickened resin loose. This was a huge pain in the ass. I had to get creative and use the straight tire iron from my chevy truck to reach in and get the parts farthest from the inside edge that I opened up. It seems some people didn't have nearly the trouble I did. I guess it just depends how much thickened resin the builders used when dropping in the inner liner. Good luck. You might get lucky and it will come out easy.