"The Kid", my 25 year old, got a fifth wheel travel trailer for free. So
far, he's taken the backhoe and ripped the whole top off. Now there's a
ripped up floor on what looks to be a decent fifth wheel frame.

It looks like they used self tapping screws to attach one layer of plywood
to the frame. Then a second layer bonded over the top with zillions of
nails. The deck is not prying off the steel frame no matter what he's tried.
He's about to say UNCLE and send it to the dump.

Any suggestions on what to try?

Karl