bathroom subfloor replacement HELP NEEDED

[rushhome6]

Hi there airstream family,
I'm humbly requesting some specific help for the replacement of my bathroom subfloor in by 75-76 Argosy '26 RB. I am thinking I will not be able to fit a new piece in the way I removed the old piece. I'm not planning on removing all the interior skins as we plan to keep the "bedroom" intact durning remodel. It seems though, in order to get a good look at the c channel, at least the bottom skins in the bathroom need removing?? If attempting to slide the new piece in from the outside is the best option, what steps do I need to go through to do that?
When I look at the exterior, I see a rail separating the exterior skin from the belly pan. I'm assuming that comes off? Does the entire circumference need removing? Do I need to remove the bumper? Should the belly pan be removed? Sorry, I know these are elementary questions- kindergarten even but I want to make sure I do the right steps to get the repair done well but without doing extra work that necessitates more demo than I need. Thanks in advance!

[Belegedhel]

The way these trailers are constructed, the interior and exterior skins are held together at the bottom by the C-channel. There are bolts that go through the C-channel, down through the subfloor, and through the tips of the outriggers of the frame, thus sandwiching the subfloor between the frame and C-channel. So in order to access these bolts from the top and the bottom, you will need to remove the lower interior skins, and at least partially remove the belly skin and side wraps/banana wraps. To remove the wraps, you will have to remove that piece of trim on the outside that circumnavigates the lower region of the trailer.

As for inserting the new floor, do it from inside, and you will probably have to split it into two pieces and then join them in the middle with a doubler. If you search for "shell on floor replacement," you should find several threads discussing the process of getting the floor back in.

good luck!

[rushhome6]

This is very helpful- thanks so much!!!