Several years ago I undertook a DIY camper roof repair on my 1994 Starcraft Stardust. One day while I was preparing to recaulk the seals, I discovered a soft spot. Closer inspection revealed several areas with major wood rot. The majority of the roof was in good shape but in need of structural repair.
The first step included removing weatherstripping on the roof and on the bottom of the walls. I then had to peel off the vinyl roofing carefully to preserve as much material as possible. I then removed the bad sections of wood:
I built a new support frame on which the roof rested over the winter while repairs were completed.
Next, I installed the new walls and tested the function of the lift mechanism.