Took me a couple of hours, more or less (a competent mechanic probably could have done it in half the time, but I didn't rush.
The part I though was going to be tough (the wiring) went very smoothly---didn't have to remove the tank as I though I would.
Fitting the actual grips required a little surgery---the throttle sleeve had a lip on the end that precluded fitting of the grip.
Also, the throttle grip required a little trimming as it was binding on the bar end, preventing the throttle from closing.
Before I buttoned everything up permanently, I backed the bike outside, fired it up, and within about 45 seconds....GLORIOUS HEAT..
Later that afternoon I saw a dude on a Gixxer 600, stopped at a light with his frozen mitts cradled in his armpits....poor bastard.
I can hardly wait to get insurance!