Another motorcycle 'must have' for me are Kuryakyn ISO grips. Nothing else feels as good in my hands...except maybe a firm set of hooters.
Grip removal is easy. Work a long, skinny flat-bladed screwdriver under the grip. Spray WD40 under the grip. Give it a minute or two to dissolve the glue. Then repeat as necessary until the grip comes off. Clean off any remaining glue.
Kuryakyn ISO grips.
I usually wrap a turn of electrical tape on the bar so the grip binds better. Spread on some of the included glue and slip the grip into the position you want. The glue sets up almost instantly so know how you want the grips positioned.
Kuryakyn Throttle Boss.