Here's the best way:
Supplies Needed:
Grips
Two-sided tape
Lighter Fluid
1. Carefully spiral-wrap double-faced tape around the shaft, from the top of the shaft to within about 1/8 inch of the end of the new grip. Make sure the edges of the tape are slightly separated -- not overlapped. If you want to build up the grip, add one or two more layers of tape to the first layer.
note: Air needs to be able to escape when you apply a grip... make sure there's an outlet as to prevent a pressure buildup as you slide the grip on.
2. Poor lighter fluid into your grip, slosh it around to coat the entire inside of the grip (about a half of a shot glass worth). Poor the remaining fluid out of the grip onto the double-sided tape, making sure all of the tape is wet with fluid so the new grip can slide on.
3. Quickly begin sliding the new grip over the tape as far as it will go. Let it cure for 2-3 hours.
4. Repeat for the other side.