Steel bolts threaded into aluminum can "freeze" into it so any attempt to remove will result in either stripped threads or broken bolts.There are many "tricks" mechanics use short of brute force. Here are a couple: Sometimes hitting the head with a hammer can shock the bolt loose. Sometimes tightening and loosening in small increments will do it. Sometimes fluids can do it but the trick is to get it to the threads on a long bolt. One of the best methods I have tried is to heat the head of the bolt cherry red and let it cool. Do it several times, let it cool and then try to remove. In most cases if the bolt is that stubborn then the best you can hope for is to strip the threads but at least you don't break the bolt. Be prepared to rethread with a Heli-coil or similar and worst case drill out the broken bolt.(It isn't easy, if you are not dead center you will wind up off center and into the soft aluminum). Since it is the fuel system we are talking about I don't think heat is an option. When reinstalling use an anti-seize compound so this doesn't happen again. David Teitelbaum vin 10757