For Class-C i would get a bottle jack with a rating equal or greater than GAWR of rear axle. Not that much more than the min needed for one side.
Harbor freight is good deal.
An important item is a large flat plate to support the jack if not on concrete.
maybe 12" x 12" 1/4" thick steel plate. Check with local shop offering welding or tow hitch install as they many times have scrap pieces available
If jacking be sure to set brake and block the tires front & back so the RV can't roll.
Whenever I change an outer dual I run a couple lug nuts on the inner (hand tight is good enough)as soon as I remove the outer, just to keep one wheel under the coach in case something slips with the jack.
If changing the inner dual I temporarily use the outer tire as safety backup.
IF YOU RUN 19.5 or 22.5 tires
I strongly suggest you get service truck and let them wrestle the 100#+ tire and wheel around also if you have lost more than 20% of your air in any tire it is considered flat and if you drove any distance on it you may have damaged the body and it could
explode when re-inflated. Inform the tech and let them inspect and re-inflate or replace. This could result in injury or worse.