taking apart Prindle 16, help with two bolts PLZ

I need help removing the bow crossbar. I have removed the two outer bolts easily, but am having trouble with the two bolts on the inside that you cannot get to from anywhere I can see. They seem to just spin when I get on them with a 1/2 socket. What can I do to get these so I can seperate the hulls & throw this mofo in my basement for winter?
nevermind, discovered you can go in through the ports in the middle of each hull. disassembled & in the basement.