Before tearing into it consider what else you could possibly do and maybe even use it as is. There is nothing wrong with fixing it if you are into that but it could be a whole can of worms. After looking at several rv's recently and finding nothing but water damage it made me wonder what happens to so many bad rigs. I cant see how most of them are worth fixing unless it diy. It all comes down to the number of years used vs the price paid. I have always been dead set against even considering anything with water damage but now look at it differently. There may be some real values out there if bought cheaply and the leak can be stopped and use it as is, as long as it's not funky inside.