I didn't pull out any cabinets. I removed the dinette table and the bench seat by the door to have room to work in. I also removed the subwoofer. Then I removed all the vinyl I could except for the bathroom where it was fine. I pulled out vinyl inside of the cabinet/gaucho assembly where I could and also under the sink. Then I sealed the exposed subfloor with one or two coats of exterior (spar) polyurethane. I did have a water stain from one side of the door towards the middle of the subfloor, presumably leaking from the lower bracket for the awning. I sealed all the awning brackets by taking them off and putting sealant under them and around them when I put them back on. There was also a small water stain next to the sink, probably from a spill.
Your trailer may be a little different, but I think the 25 FB's are pretty much the same floor plan. The gaucho cabinet in ours is covered in cloth, but I think the new flooring went underneath. The lower cabinet doors can bind on the floor if it is too thick, so watch for that so you don't have to reposition the hinges. Ours barely fit, but it worked out ok.
We found some loose lay flooring from Karndean. It has a rubber backing that makes it impossible to move if you are standing on it. I sprayed repositioning glue on the subfloor that allows you to move things if necessary. This product comes in planks and I made a jig so I could cut it with a sabre saw. To make a straight cut, a jog is necessary unless you have a stea
dier hand than I have. For cutting in tight spaces and difficult curves, I used a knife for cutting flooring. It pulls up easily and in the winter is shrinks a little and leaves visible spaces between planks. I can lift it and move it back tight, but unless you stare at it, it looks fine with small spaces between planks. This makes it easy to check under most of them for any water issues. I got the flooring from a company I found on the internet (I think it was in Ga.) and they shipped it free—considering how heavy flooring is, that was good. It was about half the price a local flooring store wanted. It comes in several patterns and colors. It look far better than the cheap OEM vinyl, but it is thicker.
I had no problem putting in quarter round (I finished sanded it and applied a couple of coats of the same polyurethane. Quarter round comes in two different sizes—3/4" and a but smaller, but sometimes you have to go to a few different lumber yards to find both. I think I used the smaller size, but I can't remember. Since I left the bathroom vinyl, I bought a metal transition strip which I installed under the bathroom door. There is a metal transition strip between the vinyl and the bedroom rug—the rug covers the screws holding it down and they were impossible to locate. So I used a screwdriver to bend it up to slide the flooring under, and then banged it back in place with a wooden block and a hammer. When I took up the old floor, I found a hole in the subfloor where the OEM transition strip is and just covered it with the new flooring. I don't know what the hole was for (to let mice in?).
Our sink cabinet is curved, so I got some rubber commercial baseboard and glued it to the bottom of the cabinet. I used construction adhesive, but one end kept popping off and I superglued it. This molding comes in black and brown (other colors are available, but brown and black are easiest to find). The brown matched close enough.
I think the cost for everything was about $250, but this was several years ago, so I may be off.
I considered taking up the carpet in the bedroom, but that means removing the bed and I didn't want to do that. I keep thinking about looking under that rug to see if there's any water damage, but haven't done more than think about it.
The jig was made of scrap lumber and was long enough for the entire plank to fit on with a space for the sabre saw (or jigsaw) to run through. Then I clamped a straight board to it to guide the saw. Worked like a dream and it took longer to make the jig than to cut the planks. It is best to make a drawing of the floor and plan out the position of the planks so you have the least waste and don't have odd sizes—the planks were centered in the hallway so the cut ones were at the edges. It also worked out well and allowed me to use the minimum number of planks. Since this comes in packages, you want to plan ahead to make sure you don't order too much or too little. These planks come in a few different patterns, so once you open the packages, it is best to divide them in piles of identical ones so you can plan out how to distribute them so you don't have identical ones next to each other.
Pulling up the old floor and sealing the subfloor took the most time. I don't know if this product comes in tiles. Tiles are easier to install, but the planks look better to us.
Good luck. PM me if you have any questions—I don't check the Forum that often.