I have acetylene torches so it's easy BUT in your case.

1. The Muffler section on the Axle pipe is Over the Axle pipe. You should be able to Hacksaw a slit down the length of the old muffler piece . It should be easy to knock off after that.

2. Same with the 'S' pipe. you will have to hacksaw the old Muffler leaving a small piece of Muffler inside the 'S' pipe. Then use a hacksaw on the inside of the 'S' pipe to cut a slit in the leftover Muffler piece. after it's cut, you should be able to peel it up a bit and slide it out.

The 'S' pipe will be hard to put on the new muffler because the Clamp mis shaped it. You may have to try and open the pipe up. running to a shop and having them use a spreader might be in order. I bought a tool but for this but you may not want to spend the money. A little dishwashing soap may help a lot to lubricate the pipes as you put them together. It washes away after one rain.

It wont be fun.

--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me