I had to replace the generator fuel pump on my o7 Lazy Daze Mid Bath. The generator is an Onan 4000 Microquiet. While from a technical point of view it is not a difficult job, it is a very involved. I took pictures with a cell phone at each point so I could find my way back down the path. On this vintage Onan almost all the wires are white so it is difficult just looking at a wire to figure out where it goes on a diagram. My LD came with the original documents provided by Lazy Daze and the Onan manuals were part of that. But the lack of color codes made fault checking and wire tracing difficult. If your Onan has all white be sure to mark them or make a note of some kind. I had a ground that needed to go to ground but was very afraid to do it. As far as other work on the generator goes, the spark plug was easy as was the oil change. The air filter is a little involved because of the tight fit. Luck was with me as my carb was not plugged up with bad gas. Though once the air cleaner assembly is off carb removal did not look that difficult. You have to get past the green hatch to do that work though.
Good luck with the RV! Welcome to the Lazy Daze cult.