or you can do what I did and pay the muffller shop $20 to cut yours off and drill the holes out. Depending on how rusty it is, and what tools you own, that may be the easiest way

 

i got under my car today to look things over and to lube my hangers, and the bolts dont really have any rust at all, just dirty. guess thats whats nice about not living near the coast, hardly any body/frame rust, if any. exhaust system and short shifter arrive tuesday, new bushings friday install on sat =D

 

Dude, screw wd-40, PB Blaster is where its at, period.

THe only problems you may run into, is seperating the cat-back, from the cat. I found it's easiest to take the O2 sensor out of the cat, and disconnect the cat from the downpipe so it all comes out together (except the downpipe). That way you can really get good leverage on the bolts that hold the cat to the cat-back. That leverage, coupled with the power of pb blaster should make the job a cake walk. But don't get discouraged if you snap a bolt or two, it happens.