These are from TOB (sorry I can't credit the author, I didn't write down his name/handle):
BEFORE:(1) Remove cans from your bike. Drill out the rivets that hold on the end pieces of your cans. Drill through the center of the rivets until your hear a splintering sound. Then you may need to use pliers to pull the rivets out. Once you have all the rivets removed, you can pop the end pieces off your cans. You’ll probably need to use a hammer and screwdriver as they’re on pretty tight.
(2) Then remove the packing from your cans. I used gloves and pliers because the fiberglass can be pretty nasty if it comes in contact with your skin. Also notice that the fiberglass is black from the carbon buildup. All of the parts you pull from your cans will be messy and leave black carbon build-up everywhere.
(3) Once you decide how much you want to chop off of your cans, wrap scotch tape around the cans so that you can make a visible cut line and dot have to worry about your CF splintering. When you mark your line measure from the back end of the can and use a flexible straight edge to make your line straight all the way around the can.
(4) Next make your initial cut. Cut all the way around through the tape and into the CF but not all the way through. I cut this with a hacksaw with a metal cutting blade. This made it so that I could work slow enough to ensure a straight line.
(5) Once I cut all the way around through the tape, I hacksawed through the rest of the CF all the way around. Take your time as you want this cut to be as straight as possible. Only cut through the CF. Do not cut through the inner pipe yet.
(6) Next slide the cut part of the can off the back. You’ll notice that in my example there’s still a heat shield that separates the fiberglass packing from the CF. If you have a heat shield in there, cut it with a utility knife.
(7) Next, pull out the inner shielding that surrounds the inner pipe.
( Then, cut the inner pipe so that is flush with the end of your CF cans. I used a Dremel tool and the cut was very easy. Just take your time and make sure your cut is even.
(9) Once that is finished, slide the wire mesh sleeve back onto the inner pipe and cut it so that is flush with the end of the pipe. Then you must decide if you want to put the packing back in the can or leave it out. If you want to put it back in like I did, then shove it back in there and cut it even with the end of the can. If you want to leave it out, I would recommend using some header wrap and wrap it around the inner pipe so that your CF doest get too hot without the packing to protect it. Then remove the tape from the end of your can and force the end cap back on. Make sure that you get it on all the way. You can tap on it with a rubber mallet to make sure is on all the way.
(10) Then drill out your rivet holes and use a pop rivet gun to replace the pop rivets. Use the same size drill bit as the size of the rivets you have. I used 3/1 (5mm) aluminum rivets. Then pop the rivets, and put the cans back on your bike.
AFTER: