Replacing a rear muffler

[KenInNC]

So, hi there. I have a 1980 Fiat Spider 2000 (the fuel injected model). I'm working on replacing the rear muffler on the car and need some help/advice. So the rear muffler has 3 parts i guess you could say there's the tail where the exhaust comes out, the main muffler compartment and then the pipe that leads up over the rear axle. So while replacing the rear muffler the old one shears off between the rear pipe and the main compartment. Now the old one is completely broken. The problem here is I can't get off the last bit of the rear muffler. I've tried using many methods to get the last bit off and it really won't budge. Upon closer inspection I think it may even have a little spot weld holding it on. Can anyone give suggestions for removing this part or tell me what I will have to do if it is welded on.

I wanted to include a diagram so it was easier to tell what the heck I was talking about, but I could not figure out how to include an image.

[azygoustoyou]

You may have to grind it off. If you have a chop saw. Just chop off the end of the mid section. But make sure you leave enough for the tail section to still go into the mid section.