start pulling interior panels until you get the wood all exposed up there, and see what kind of damage you are dealing with. It is often much worse than you think.
😞There are many folks here who have been there, done that. If you are a handy sort of person, it's not that difficult. Time consuming and frustrating, but very doable.
and post some pics of the damage, we like pics. :B
2004 Fleetwood Tioga 29v