Grips are expensive enough for golf clubs and instead of destroying perfectly good grips when you need to change them for new clubs or want to extend/reduce the shaft of your golf clubs you don´t always need to buy new clubs.
This is the simplest way of removing your golf grips in one piece and restoring your golf clubs without having an air compressor to hand or additional tools.
You just need a strong metal tool, a coat hanger should be strong enough metal one of course, or you can have a grip removal tool, I happen to have the latter as I do this quite often so did invest in one.