In the mobile home I just bought they people used to keep their wash machine in one of the closets. Apparently at some time the machine leaked because the floor is quite damaged. You can tell it was once wet, but is quite dry to the touch. There's linoleum floor over the wood, but the linoleum is curled up. It also smells a bit musky, but I don't see signs of severe rotting or mold. My husband wants to cut the damaged wood out (a piece about 3x3), but neither of really knows how to go about it and need to stay on budget. Does anyone have any tips on how to do this ourselves?
You say your floor in the closet is quite 'damaged.' Yet you also say it is dry, yet musty, and the vinyl is curled up, no signs of mold or severe rotting. These are normally made with partical board floors and they build the walls(etc) on top of the vinyl which usually tends to curl up on the edges where they didn't glue/roll it well enough(knowing it was going to be under carpet) as modulars are built on a "production" line.
If your floor isn't 'soft'(dry rott), spray some bleach on it to kill the musty smell, then seal it with a recommended sealer that will also inhibit the growth of molds.
If you must replace the floor you might need a carpenter that knows his thing. Remember, if you do cut out the floor, watch out for wiring/ plumming as a lot of times that's done before they insulate the floor and it can be very close to your cutting....