That's a very good one to read for shell off! He's a brave man to raise a 31 footer!
We were more chicken, and did our's shell-on. Here's the link http://www.airforums.com/forums/f185...urb-50967.html
Everything is riveted so it's a matter of drilling out rivets to release. You will need to take the lower inner skins off to access the C channel to get the bolts and screws that hold the sandwich of the frame, floor, and C channel/trailer walls together. Some people have left the belly pan in place to do this, but we did remove ours (warning - not a fun job).
If you run into problems or questions - post pictures and ask! There's lots of help on the forums, and lots of us doing what you're doing in various stages. Feel free to PM us also!