I just cored my 1999 750SS this afternoon. -Figured I'd share the story.
I removed the exaust and there was a mounting braket on the sleave left over.
I removed the mounting bolts from the tab itself, and one of the bolts broke off inside the can when I was using the impact driver. oh well.
Then I drilled out the 3 rivets on the cap.
I hacked away gingerly at the aluminum cap with a screw driver. Then I struggled for 10 minutes with a buddy trying to remove the sleeve. I put it in front of the garage heater for a minute and then it was nice n hot. -came off easier.
I drilled the main pipe off in the first chamber using a saws all and a circular grinder. Then cut a hole in the end where the cap attached, and the little pipe slid right out, leaving a nice deep chamber. The other pipe got cut too, and, as you may notice there are two little pipes within the exhaust. some people only cut one...I cut both. No worries. ...anyways
I'll make a long story short and say it went ok. just exhausting though, no pun intended. I screwed up once when putting the sleeve back on, and the holes for the mounting tab didnt line up, so I had to struggle for another 10 minutes, lol. but it went back on fine, and bolted right back up.
The sound is awesome. The fiberglass wrap I found under the sleeve was a pain in the butt, and I only ended up using half of it when I reinstalled. I'm doing the other one tomorrow. Sounds nice n deep, but not too loud.