Quoted from DrJoe:Install one end of the Super-Band over the fat end of the flipper bat. From behind the flipper, push the Super-Band with your thumbs over the tip of the bat. Make sure the Super-Band is all the way down on the bat. Avoid using tools as this could damage your playfield.
This is indeed the easiest and gets easier the more you go it... you don't need to put your thumbs INTO the band as you push - just push it along the top of the flipper with both thumbs. If you can get it over the tip you're golden