According to "Minimizer" they have two wheel well mounting kits... One is a "weld on" and the is a "bolt on" type. (It would seem to me that the bolt-on's are easier than welding...
As far as access, when I changed out my air-bag helper shocks, I chocked the front wheels really well and blocked the rear jacks (built up to the jack before lifting the rear levelers... That gave me plenty of space when the rear axel dropped down.
Just make sure you jack stand the RV frame once you get it in the air, for safety!
These installation instructions
are for the Minimizer brand truck wheel well mounting kit, but your RV can't be too much different...