starting from the rear of the pipe, there should be a ridge between the first weld line and the first heat shield mount. you need to cut the pipe on both sides of the ridge to remove that clogged cat converter.
1) cut on the rear edge of the ridge, stay very close to save the rear cone thats hidden inside the pipe. you can see the weld line on the peice in my hand and the rear heat shield mount on the pipe.
2) if you masterfully cut that rear section off, then cut on the other side of the ridge, like 3mm over. the cat converter (on the bottom) was removed from between the center peice and the right piece (both on the top row). Ignore that leftmost cut, it was erroneous.
3) weld it back together! make sure that hole on the rear is rotated towards the ground.