How not to
I think there is lots of "how to info" here, so I'll give you the "how not to" info.
1. Don't loose the hole saw inside your muffler. Most attach to the drill with a set screw. Drill an indentation in the drill bit where the set screw sits, and use locktite on the set screw.
2. Don't let the extention spin on the drill bit. Drill an indentation and use locktite on those set screws.
3. Don't freak out if you lose the piece you drill out. Try not to lose it inside by adjusting the drill bit 1 inch longer than the hole saw. If you lose 1 or 2, nbd, they won't hurt anything.
4. Don't tell you wife, no good can come of this.
