Okay. I've had mine apart a couple of times. Behind the filter is the pump(also made of plastic). It's connected to the drum by a rubber hose with a couple of squeeze clamp. Also connected to the back of the pump is the drain hose.
When I had mine out to fix the dryer problem, it was in and out a couple of times, plus the guy pulled it out when he was fixing the plumbing.
When I finally got it hooked back up, it would leak when the water was being pumped out of the washer. What I found was that in removing and installing the thing, too much pressure had been put on the drain hose and it was almost pulled off the nipple. Enough so that the water had started bypassing the clamp. I reseated the drain line and it quit leaking. Of course, this was after I'd had the local heat and air place make me a drain tray for it.
To remove the machine: Pull the wooden retainer bar off the front. Grab the washer and pull it out a few inches. Remove the access panel in the water closet. You can access the electric plug and the shutoff valves through there. You can also reach way up in there and access the drain line to pull it out of the coach plumbing. Go to the outside of the coach and remove the exhaust vent. You should be able to pull it out enough to disconnect the flex duct from the vent(leave it with the machine). Once the vent hose, the electric plug, and the drain hose are disconnected, I had enough slack in the water hoses to pull the washer all the way out. Once it's out of the hole you can disconnect the hoses.
The pump and all the plumbing can be accessed by laying the washer on it's side.