Grip puppies are made to reduce handlebars vibrations on the grips preventing hands fatigue. For riders with bigger hands they also may provide a better comfort because of the increased diameter. Someone may argue that they may also endanger the feeling of the front end but in my experience that is not the case or at least there is enough good feeling in a regular traffic riding. Sports riding on a track is probably different story.
First remove the bar end finisher using 4 mm hex key.
Then remove the mirror using 5 mm hex key. You may want to mark the position of the mirror for easier setting back to the right place. Or simply make a photo.
Spray some soapy water onto the grip and inside the grip puppy tube to allow easier pulling on the grips. Using this technique it is quite easy to install them.
Install the mirror back to the same position and tighten the pinch bolt to 3.5 Nm.
Use some medium thread locker for the bar end bolt and torque it to 5 Nm.
I like grip puppies since I discovered them probably somewhere 2015. I hope they will work well on the Rocket bike as well. If you are wondering do they prevent heating on the heated grips, the answer is no. The heat spreads through grip puppies no problem. You maybe have to wait few moments longer to feel the heat but after that it works just like expected.