I re-grip my own now. As others have said, it's pretty easy.
To make quick work of taking off the old spent grips, use a hook blade in your utility knife. You'll find them at you local hardware store. Be especially careful not to cut graphite shafts with a knife blade. To avoid that, insert the hook under the end if the grip with the blade tangent to the shaft, and keep it tangent while you slit the grip open.
The toughest part for me has been getting the old tape off. There are tape removal tools that make that a lot easier, such as these from Golfworks and Brampton, or you can make your own from an old shaft. It also helps to warm the tape a bit before you try. A propane torch works well for that, if used carefully.
Grip solvent will take off what you can't scrape off. By the way, paint thinner works as well as grip solvent for that job. It also works just as well for installing new grips over fresh grip tape.
That is all easy enough, but it's messy and you need to wait a few hours for the adhesives to set. But I think I've found a better way. (Thanks to the friend who led me to it!)
Now I use a compressor to blow the old grips off and the new grips on. Instead of using grip tape (with adhesive on both sides), I now use pieces of 2-inch wide masking tape cut to the length of the grips. That way, if I'm only replacing worn grips with new of the same model, I don't even have to take off the old tape. How to air-install them is shown in this video.
Instead of that special airgun shown in the video, I just use one that came with this $15 air compressor starter kit. To help keep the grip from flopping around and buckling during installation, I slip a piece of PVC pipe over it that is a couple of inches shorter than the grip. (1 1/2-inch Schedule 40 PVC pipe has an average inside diameter of 1.38 inches; it fits nicely over my midsize grips
I have been using Pure™ DTX grips. That is the same brand as used in the application video. I like the way they feel and they last a long time. Two years ago when I last bought grips, they were pretty economical two years ago ($60 for 13), but the price about 50ﬁ higher now. I have heard that grips of other manufacturers can be applied the same way.
I blew on my first set of grips with a $15 12-vdc emergency tire inflator. It worked, but it was a bit of a struggle. Since then, I purchased a pancake compressor for other reasons. It can deliver 2.6 SCFM at 90 psi and it works much better on installing grips.