Let us know how you make out on removing the exhaust cover screws. There are usually a few of them that will present a challenge. Here’s a pic of a real crusty one I had a few years ago – even using the torch I had 3 break off and 1 had a boogered up head on the screw I had to drill off. Once I got the cover off, I got them all removed with the torch, penetrating oil and lots of patience. Yours look like they should be much easier to get out.
Ooooh, that’s a crusty one for sure… Glad it seems like the screw heads snapped off leaving exposed shanks once the exhaust cover was removed. Removing that cover must have been a chore in itself, the salt locked it in place I’m sure. I would have had no problem just “wasting” that cover with an air hammer/chisel to expose the studs so you can have round two with the vise grips and torch. Hope it worked out finally.