My favorate tool is my HD snap-on air hammer. It has all kinds of uses. Also you could try a good impact 1/2" or 3/4" like a snapon at about 160-185 psi. Once the bolt spins it will come out. If you use a torch the rubber bushing will light on fire- this could suck real fast. Marinate the bolt / bushing for a couple days with good penetrating oil. If all elce fails get a 3/4" breaker bar and a 5 foot cheeter pipe. The air hammer will work. You might have to cut the head off the bolt and hammer out the stud if its pointing toward the rear.
Real hummers dont have leaf springs or solid axles.
Ian Ward
Rollin Road Service
281.802.1131
Iandanielward@yahoo.com