Removing the grips w/o F'ing them up. Start with compressed air. Blow with a fine tip nozzle into/under the grip and see if it will loosen and allow you to pull it off. If they were aggressively glued on, this won't happen.
Next step, CAREFULLY use a long, thin screwdriver to work under the grip and work your way around the end of the grip to break the adhesive loose, then start going deeper and working it around the grip to break it loose. Don't get too carried away prying against the grip because the element makes it less flexible than a standard grip.
Then return to the compressed air nozzle and it will help inflate the grip slightly and often allows it to pull over w/o much effort. I try to block the inside end with my hand or a helper's hand to allow the air to balloon under the grip a bit, which helps.
Re-installing the grips - Use some hairspray for lube and when it dries, it will act as a mild adhesive the keep them from rotating w/o the need for safety wiring the grips. Often there is enough residual glue and tension that it's not an issue anyway.
When you buy factory heated grips to install yourself, the throttle side comes on a throttle tube. Nice, unless you're a dumbass and let it get knocked off the work bench and it breaks the throttle cable tab.... I had to remove the non-heated grip and remove the heated grip from their prospective throttle tubes, then re-install the heated grip on the old throttle tube. Did OK, still works!
In your case, swapping bars, you won't need to take the throttle side heated grip off, just remove the throttle tube from the bars. You'll only have to work the clutch side off carefully. Which is definitely the easier side! I just use the air nozzle technique to install the grip too, no adhesive or lube needed and it didn't move around despite never having glue on it.
Tip: Lube the heated grip wire on the throttle tube where it moves in and out of the housing when you re-install it. Some white lithium grease or similar works fine. That helps avoid breaking the wires with throttle movements. (and is part of the factory procedure)
Hope that helps.