When installing the grip puppies, do yourself a favor!
Soap them up inside with a coating of soapy water, to give a little slip to get on.
BUT ALSO
Get a straight piece of metal wire, like an unbent wire hanger, and put it through
one of the grip puppies. When you go to put it on the grips, press the wire
towards the inside of the handle, wear the clutch oil or front brake oil reservoirs
are and then begin sliding your puppies over the existing grips.
Basically what I am describing here is a narrow channel of air, so that you don't
create a vacuum barrier that becomes VERY resistant about half way up the grip.
Even though you have a thin layer of soapy water for lubricant, if you don't use the
wire technique, it's similar to putting two tupperware bowls together (one nestled
inside the other) and trying to put them apart. The more pull you apply, the more
the vacuum holds them together.
ALSO, use a shimmy wrenching motion as you snake the grip puppies over the
old grip. Like revving the throttle of your bike, it shimmys it's way up the existing
grip.
Make sure your hands are strong and have fun!