Floor Rot

I just recently tackled this same thing along with much much more! lol....I totally gutted and re-did what I think is a 1972 Coachman knight. Anyway yours actually looks pretty good. The easiest thing to do is cut out all the rot until you reach solid wood and then once you pull up the rotten wood you will see how the floor is framed together. After removing the rotten flooring and frame it's pretty easy then to just tie into the good stuff and lay down a new piece of floor. As far as the tank it's hard to see exactly in the pics but you may find you won't have to disturb it at all to replace the floor. Good luck and just dig in. It's really not a bad job.