Silde Out Floor

I'm not sure if this is the right place to post this but here goes. Spring is getting close and I need to replace the floor in my 5th wheel slide, 12 footer. I have already removed the furniture and the dinette and carpet. Waiting for the weather to get a little better before I remove the cover and extend the slide. The floor is only supported by the 3 outside walls and sets on the sill of the trailer when out with no cross supports. Has anyone here done this without removing the slide from the trailer. Any information and advice either way, removing or not, would be appreciated, not trading units. Thanks