Just work them back and forth by hand until you can twist them off. I used GooGone to get the adhesive off. I don't trust GoofOff, it can destroy some surfaces. If you have a heat gun, heating them up a bit first works very well, but don't overheat plastic or paint.
Once I got started, I got rid of all those damned stickers that litter the bike.
I also found some black vinyl sheets somewhere online that you can cut into any shape you like which reflect white. During the day, you can't see them on the frame, but at night they glow bright white when hit by headlights.
If anyone is interested, I can try to find the link.