After many months of procrastination, I finally went after the "bolts" for my exhaust to put my M&K premuffler and muffler on. Armed with advice and various methods, each bolt presented its own special challenge. I tried all the tricks--soaking fluid, nut extractors, 3" grinder, dremel, air chisel and punch. I got creative in splitting the most resistant nuts with the chisel by grooving them and then changing the angle to "loosen" the nut. This split them and then they came off with pliers. But even then, some of the bolts were so nicely bonded to the exhuast I had to heat them, hammer them, punch them, swear at them, but eventually they all yielded.
Today the muffler!