I replaced the entire front steel floor section on my suburban - with minimal bracing at first. I put the doors back on - and used a couple ratchet straps to get the gaps close and then welded a couple braces. All of this after the fact of cutting out the old floor...and wish I knew that beforehand. Just like woodworking nothing is fatal except a good fire - but there are some things to prep and think ahead of time to prevent a lot of work later. So - rehang the doors - check the gaps, make sure it is latched - use what you have to push, pull, adjust, and get them close and brace it - then do the same on the other side.
I give you a lot of credit - what you're doing isnt' for the faint of heart - but do-able. The trick is to think three steps ahead.
