Get a saw...
As you face the stern on the right past where the sink goes, I sliced down through a fiberglass "wall". I pushed it down like a flap and slid on my belly back to where the mount attaches. Bring your tools and while you are there check the hose that goes from your cockpit to the drain hole. The clip on mine had fallen off and the cockpit was draining into the bottom of the boat. There didn't seem to be a big piece of wood but I do remember really thick fiberglass. I might have even had to drill some new holes. Have a buddy outside while you are doing this. 10 years ago but still vivid....Good luck!
