Welcome to the forums! There are many folks who have completely redone their interiors and floors, as well as wiring, plumbing, etc. I suggest you use the search function and see how different folks have approached replacing their floor or portions of their floors. My husband did a complete disassemble on our vintage 1963
Bambi (certainly smaller than yours!) and has lots of photos and explanations of different things he did. Although ours is smaller, many of the processes one goes through will be similar. Take a look. Warning! It is a long thread! http://www.airforums.com/forums/f36/...mbi-17925.html
Any specific questions and folks will answer. I would be sure that your Airstream is leak proof or can be indoors in the winter before the weather turns bad.
When you have specific questions like "floor replacement" use the search tool at the top. It will give you all threads with those words but if you browse you might find things you need to know! If you can't find an answer begin a new thread with part of what you need, like ~ need help on new floor ~ folks will see the title and click and likely answer promptly.
Good luck! Post photos when you have questions as well, it always helps folks give best responses!
Mrs. NorCal Bambi (traveling in S Tardis)