From Jim Davis's instrument cluster article—http://hrsbstaff.ednet.ns.ca/bvogel/K100/Fixing-the-speedo/k_bike_speedo_repair.htm—here's his tutorial on needle removal:
In order to determine the problem that your unit has, you may have to take the speedo needle off to get the speedo's face off. I pried very carefully but forcefully with two small screwdrivers on each side of the needle, using a piece of stiff paper under them to keep from marring the face. It will come off, be brave.
:yow