Originally Posted by aBoyAndHisCJ
try Vise-Grips from underneath since you can see they all stick out pretty far beneath the tub
If you can get some one to help you have them hit the bolt from inside of the Jeep with a propane touch. This will keep the flame away from the fuel tank since you are worried about it. If you broke the heads off I think you will need heat to get these out.
As for vise-grips they may work, but I would use a pipe wrench. Use the biggest on you can get on the. The have better bite then vise-grips.
Between Heat and a pipe wrench they should come right out.