1. Use a hack saw on the aerobars just behind the shifter.....done!!
or
2. Just whack the hell out of them with a big hammer.....done!!
SORRY......couldn't resist....
The above poster is right on. After some time they might get a tad stuck in the aerobar end, so you may have to twist them out after loosening the bolt inside. . . Paul
The allen bolt inside the bar end shifters needs to be turned the opposite way to loosen it. To loosen it turn the allen wrench clockwise so that you can pull the base of the shifter out. -Darrell