Of any place I would think that would be the easiest place to replace the floor. The slide on that side rolls completely off the floor. It depends on what year and model you have. You can make slide jacks to raise the slides off the floor without removing it from the coach. If you look through my posts I have given detailed instructions and pictures on how to build them and use them. I love Newmar slides because they are easy too work with and on because of their simplicity. Obviously you have a water intrusion problem that needs to be addressed on the salon slide. Good luck.
Craig & Carolyn Roberts Apple Valley, CA
Toad: 2017 GMC Canyon 4X4 Crewcab