I had been spraying PB Blast all over the bolts on the exhaust and other random places just in case I needed to remove parts. It helped greatly. I decided the removing the section before the part came was best. That way I could immediately put in the new section upon arrival.
I started by removing the bolts to the C clamp. That came off easy. If it hadn't I would have just used a cut off wheel. Next up were the four bolts attaching the catalytic converter. The two bottom bolts came off like a charm. Fiat had installed clips to hold the bolt while you turn the nut. It's a great concept unless the tabs are old and don't hold the bolt. There's little room for tools on that side, so the last two bolts were easily cut away with a cutoff wheel attached to an angle grinder. The only thing left to do was to wiggle the section back and forth until it came free of the muffler.
Auto Racambi was FAST with the delivery. It went in easy in reverse order. I used four stainless bolts to fasten the section. The hardest part was wiggling the new section into the muffler pipe. I don't think this project even took two hours and it was much easier than trying to tack in new pipe and welding.