If the floor in a panel is the same dimension as the plywood floor in a suburban, you will not be able to get it out through the top or through the bottom, unless you cut it. If someone has personally gotten a plywood floor out of a panel through the bottom, please respond - this was impossible with a 1954 suburban floor with the body off the frame. The suburban body curves inward under the floor (at least, on a suburban), making it impossible to maneuver the floor out the bottom - unless you first do as described in the next paragraph.
The only other way to get the floor out (besides cutting the floor, as described by ZooKeeper), is to remove one of the metal edging strips that is spot welded to the inside wall, above the sides of the floor. This is a major undertaking (for most people) because you would have to cut out about 28 spot wields.
Refinish the floor in place (as you have already concluded). On a suburban, there is a linoleum mat which is not so easily refinished as is a panel floor.
