You don't have to be a gorilla to install even the heaviest tire/wheel combination. Loosen the lug nuts slightly before lifting the wheel Then
lift it off the ground only a fraction of an inch. Just enough to get the weight off the tire. After removing the lug nuts you should be able to remove the old one by just pulling it off the studs.
When mounting the replacement roll it into a position where the holes in the top of the wheel align with the studs. Then slip a bar under the tire and lever it into position. Once it's hanging on 1 or more studs install a nut to keep it in place. Then you can wiggle it around to align the remaining holes in the wheel with the studs.
If you watch it being done at the tire dealers no one is attempting to lift and install a 22.5" tire the same way they do a 14" passenger car tire. All it takes is a little planning and leverage. I've changed thousands of heavy tires over the years. I learned very quickly that brute strength was not the proper method.
To loosen and tighten the lug nuts I use a torque multiplier like this one.
http://www.northerntool.com/shop/tools/product_200315001_200315001
You'll also need about a 6" extension and the appropriate size socket to fit the lug nuts. Granted it's not the easiest or cleanest job, but it can be done with a minimum of strain if you follow the proper procedure.