I have general ideas and knowledge. Fixing the floor is not difficult cut out what is ruined and replace the flooring with something you want. The hard part may be finding the leak that caused the problem. Remember water always runs down. It could from a roof leak, window leak etc. Water can be running down inside the walls and not show signs on them. Check around where the walls connect to the floor on all sides near that wet area for water. Good luck
2013 24RKSWE (27ft TT) Cougar 1/2 ton series
2013 Ford F350 4x4 CC 6.7 engine, 8 ft bed 3.55 rear end lariat package
Retired from Oregon State Police in 2011 than worked another 9.5 years as a small town traffic cop:
As of 05-2020, I am all done with 39 years total police work. No more uniforms for me.