Remove Stock Grips
Throttle Side
The throttle side grip end cap will unscrew.
There might be some glue on it, so keep twisting until it breaks free. After you do that, you can get a screwdriver under the rubber to separate it from the throttle sleeve.
You may want to put some WD40 on the screwdriver. Work the screwdriver around to break the glue. There is more glue on
the throttle side than the clutch side.
Clutch Side
On the clutch side, the end cap does not screw on. Rather, it has two one inch pieces that fit into a molded slot in the rubber.
You can get a screwdrive inbetween the rubber and end cap and pry it off. Once it is off, you can get a screwdriver under the rubber (between the rubber and bar) to break the glue and twist the grip off.
Install New Grips
Before putting the new grips on, clean the parts of their original glue. If you use the glue that comes with the grips, be careful. You may shove glue up against the switch housings. Then you'll end up needing to loosen the housings and cut the inside of the grip from the housing.