I have a 1975 fibercraft boat. I need to replace the seats. It is the kind that unfolds into a bench and is a back to back seat folded up. I need to take it out but when i looked at the wood the cushion is attached to i noticed the wooden frame isnt screwed into the boat. Instead it is molded directly into the fiberglass of the hull. My boat doesnt have a floor its just the hull that you wal on. How do i remove this seat. I cant just buy new cushions.