Home Skillet hit the nail on the head --- the difficulty with this job is the "rusted bolt problem". Some part or another is held on by 4 bolts. The first three unscrew in two minutes. The last bolt either takes an hour and a half, or strips out, or snaps off. Ouch. Game over.
Before you start, stop by the RV storage lot and spray every bolt or nut with penetrating oil, liquid wrench, PB blaster or an equivalent. DO THIS EVERY NIGHT FOR A WEEK.
The parts you mention are just bolt on stuff, not especially difficult. I hate working on vehicles. But, for $3000, I think I'd attempt this work.
The only job I question is the water pump. If it was replaced in 2004 or so, why replace it now? How many miles has the RV had since then? Our 2002 gasser only has 40,000 miles on it. I'm not swapping out the water pump any time soon (I hope). Good luck.
