any place that sells tools........i work on helicopters, and we have alot of huge bolts etc...and anytime we've dropped engines you have to loosen all screws first, and lift up on the engine. Now a trick i use to break loose tight bolts with out a breaker bar, is keep the other bolts in, and get a wrench put it on the one your getting off *also i'd tighten the others in a little just in case. But take your wrench and put it on the one you can't get off, and use a rubber malet and hit the wrench the sudden impact will jar it loose. I'm sure it doesn't have as much stress as a huge turbine engine from our little 2.0 I4 cylinder. Try that man. Just tape the wrench hard with the mallet after the other bolts are back in a little tight. Just to get it loosened........