It's much less satisfying but leaves a lot of authentic looking scratches and stuff on the bar if you just latch onto that end cap with a set of locking pliers and start twisting and prying away until you finally break off the little bolt holding it on.
My MBars are freshly installed, I'm off to see if I actually like them (and to get parts for the Nap install).
Clue: To get the left hand grip off, use that ever popular chain lube/helmet deodorizer/fuel additive/fender polish/gum remover, Dubya Dee Forty - wrap a shop rag around the grip and squirt a little in the gap between grip and bar (on the inboard side), twist that part of the rubber back and forth a bit, add more Miracle Product as it loosens, then take the whole bar off. Once the bar is off, you can turn it end-up and get a little bit of Wonder Sauce in the gap between the grip and the bar on the outboard side, a few more seconds of twisting and Viola!!