about 2 weeks ago my brothers 88' integra backfired so hard it blew a whole in the muffler and broke it in half, we finally found a new one to put in but yesterday when we were tryin to take out the old one the bolts were rusted to ****, they wouldnt move at all, is there anything i could use or buy to get them lossened enough for me to unbolt them????
thanks

 

use some penetrating lubricant.

spray the nuts in question abundantly, let it set for 30-45 minutes, then come back, spray again, and if they don't come off now.

you are going to need some head to expand the nuts and see if they come off then, or you could just cut them off (hacksaw), I am assuming the new muffler came with new clamps and all that?