take off the fibreglass side panel, separate the top and bottom, or both?

You always find nice suprises, right?

So, I knew that the wall layers were fiberglass, thin plywood, styrofoam insulation, thing plywood, and then vinyl "wall paper".

got to tearing the inside apart, took the kitchen window out. Plan was to rebuild that wall, and completely gut and rebuild the bathroom. The lower beam is rotten, so was planning on separating the 2 halves to be able to access and rebuild that.

Except - the kitchen wall has small sections of styrofoam, which are inbetween the steal beams that make up the top half. Replacing the outside piece of wood? I'm not sure how I'm going to get it in there...

So then I though - the fiberglass is mostly detached anyways - why not just take that off, and then I can replace the beam/etc without having to separate the halves. So I start removing the trim that holds it on. Get the bottom off. Take off the cover for the trim on the end, and all the screws are rusty. They're either breaking or stripping. This is going to be a pain in the a$$.

So now I'm not sure how to proceed. there's a part of me that says strip it all down, if the screws are that bad, that needs fixing anyways. But that's a TON of work. The other part of me just wants to go camping in a camper that doesn't have mushy walls and a leaky roof.

Help??

My ex came over and helped me decide. Just going to separate. I can cut the wood (the original isn't really wood - not sure what they used) to go between the fiberglass and styrofoam into smaller pieces to slide it in. So Monday we separate. Tearing out as much as I can of the kitchen wall and the whole bathroom until then.