removing encoders from motor shaft

I have the same problem Terry described removing delicate glass
encoder wheels from old plotter servo motors. I successfully removed
one that was already broken by gently prying it off with a little
stanley nail puller. It takes a little pressure to break the RTV-type
adhesive, but once you get it going it comes off smooth. It is very
dicey however, the encoders on the ones I have are only .007" thick. I
think there is a better way.
I am going to make a wedge type tool to remove the other encoders,
like a Jacobs taper chuck key. Looks like a little horseshoe with
shallow ramps on both sides.
Good luck.