I can see the last picture you posted, but none of the prior.
I just got mostly done with my Norcold 1200 to Samsung RF18 conversion this weekend while the weather was nice here. I need to take a picture, but basically I removed the old Norcold which consisted of disconnect the gas and water lines, disconnect two 120v plugs, and remove all the mounting screws in front under the trim piece, and two screws at the back. I removed the doors from the Norcold and the internal shelves. Then just slid it out and then out of the MH.
The conversion for the new bigger size Samsung required a significant amount of cabinet work to lower the mounting floor and increase the opening size. On my MH there were two drawers approx 8 inches high below the frig, and then two smaller cabinet spaces above the frig around 5 inches height. The difficulty is those bottom drawers are short length, as heating ducts and some water lines run behind the drawers and under the frig. So I could not just eliminate the drawers, I still needed to have space for those ducts and lines. In addition, there are the two vent pipes going up the wall for the grey and black tanks, and they sort of 45 deg degree at the height of the old frig floor. So between the ducts and the tank vent pipes, I could not go all the way to the floor. I ended up figuring out I could use the pieces of wood that made up the top cabinets, with cut down height drawers, so I now have two drawers approx 5 inches height that use the doors from the cabinets. This gave me minimum height for the ducts and lines, and using some creative notching of the plywood base for the vent pipes, I could make the new floor about 3 inches lower than it was before. Eliminating the upper cabinets was no real loss, and i was able to reuse the piece going across that previously was the piece that was on top of the lower drawers. That piece just sits flush now at the top of the opening. In the end, I gained the height needed for the Samsung, still kept the lower drawers. I sealed the top vent opening with some styrofoam form the new frig packing, and glued in place with silicone caulk. Still need to make a permanent seal for the MH side lower opening. I did have to make a bit longer plywood floor so the rollers and mount brackets for the Samsung would sit right. Still need to paint that piece and maybe cut it back some to be more stylish. It is bare plywood now.
I removed the doors from the Samsung and was able to get it through my side door without too much problem. The lift into the opening and once adjusted into position, I used the factory front leveling feet brackets to mount it solid to my base. The factory brackets have feet, but I just drilled holes through the plywood and put bolts up through, sandwiching a 1 inch spacer. New frig is not going to come out, although I should maybe add a top bracket, just for insurance.
I still need to do the wiring, and the inverter mounting. Just happy it is all in place now and I was able to do it without major wood work, reusing those cabinets door fronts with the shorter drawers has it almost looking like it was designed that way.
I will try to get some pics, I was too busy doing the work and forgot to take pictures during the process.