Altough others have answered with great tips for other types of grips...
I used a mallet and a large socket which fit on the round end of the grip.
All the compressed air, soapy water, hair spray in the world will not slide those grips on.
If you are not using a true BFH, then you are using the wrong tool for this job.
I did two sets of them on two different bikes and the fit was more than snug.
I feel bad for the poor guy who has to remove them later.
But the feel of the grips is better than stock. The added diameter is nice.
The heat is pretty good but not as hot as I would like.
They do look good on a bike, as well.