Hey Bdubya, how is ya?
Well, first off, as you can read, there's all kinds of opinions on;
1. Whether to do it yourself or not
2. Whether to use the "floor jack" or not
3. Whether to use the coach jacks or not
and a whole lot more. Well, this is all a matter of "comfort zone". Many folks do tons of their own maintenance and repairs on here, many other RV forums and, many not even on any forums. And, they don't always go BY THE BOOK!
Many, like me, step OUTSIDE THE BOX in all kinds of situations. It's how I've gotten things done forever and, being able to afford things. I've used Harbor Freight jacks and, they work. I carry a Low Profile 20 ton unit in the coach, for whatever type of need it may work for.
Now, I've also used my coach jacks to completely lift the tires off the ground in my RV garage to do maintenance. Iv'e done it several times, I'M STILL ALIVE! And, so is the coach and all it's systems. There are some considerations and precautions to take in.
As for the "Torque Multiplier", well, that can mean a few different tools. The kind I own and use is phenomenal in how it works and, the labor it saves. M lug nuts are on with 450 ft. lbs. of torque. If I try and break them free, using a regular 3/4" breaker bar, I have to add a cheater of about another 2-3' onto that handle and, I'm still straining a n..t doing it.
But, with that version of the torque multiplier, I can sit on my a$$ and, with one arm, break loose, all 10, 450 lb. lug nuts, in about 8 minutes. And, not even break a sweat. The picture below is what I'm speaking of. I got it off ebay for about $130 or so, can't remember, it's been a while. Anyway, if you've got any questions, pm me and I'd be glad to help.