Go to a truck parts store and get a formed steel axle nut socket of the appropriate size... take it home and cut the 3/4" drive bar out of the end of the socket. Then weld the end of the socket into a piece of plate with a full diameter pass through in the socket. You can also weld an old socket of an appropriate drive size for your torque wrench onto whatever you use for a lever on the socket... and figure out the distances for the appropriate torque setting. Then you have the tool you need.
Once you remove the nut you'll need a press to force the shaft out of the hub. You'll probably need to drive a couple of wheel studs out to facilitate setting this up in a press... and it's going to take 15-20 ton push to move it. Be carefull to support it correctly as you don't want to break the hub... Then reassemble in reverse. Probably warm the bearings so they'll drop in place.