Leave them. Sorry, I know that's not what you wanted to hear. But they're just so cool.

I wonder if there's a way to get them off without hurting them. Soak the whole handlebar in a hot bath to soften it up as much as possible, work as much water under the plastic as you can, loosen up the brake lever all the way... maybe you can get the lever body (not the clamp) out? Then work the bar wrap off. If I were dead set on getting rid of the bar wrap, that's what I'd do. If you ruin it, well, then you can get our the razor knife.