I just did the grips on my 2012 Voyager. After loosening the throttle cable, pull the cable ends out and the whole factory grip slides off. Just slide the Kuryaken on, reattach the cable ends, adjust out the slack and reassemble. There are some really good videos on youtube showing how to do this.
I installed www.coolsac.com
custom braided grips so install is different from the Kuryrakyn grips.
I cut off the rubber portion from the throttle sleeve and after a little prying I was able to twist off the end cap just like the clutch side. Does have reverse threads on it. The inner ring had an O-ring so I had to pry it outboard a bit then I cut it in two with a pair of dykes. Directions say to remove the ribs from the throttle sleeve which my dremmel with a sanding drum made short work of. After I cleaned up the mess from the dremmel tool I tried to dry fit the grip on, no glue needed that sucker is on tight.
Clutch side was more straight forward just twisted off end cap then cut the rubber portion. The inboard ring was thick and the factory glue was very strong. I pried it away from housing a bit the tapped of with a brass punch and small hammer. After removing glue and cleaning up bar I dry fitted the grip and again no glue needed. After wear and weather I may need to remove and add glue but right now they are holding very tight.
1. Put some tape on switch housings if you pry the inner rings outboard. I did on the clutch side after some light marring on the throttle side. A little paint will fix it.
2. If you use a dremmel tool to remove the rips, cover bike well and wear goggles. Very messy and even with safety glasses on I got plastic in my eyes. Might be easier to remove sleeve the work on table.
All in all not to hard, I took a short trip and my hands did not go numb. I think they look great, very comfortable and I also added the lever covers from coolsac as well. Coolsac makes their grips a bit longer for the Voyagers so the problem with the weight for other grips was not an issue.