I agree approximately with Deejay's prescription for removing a Woodruff key, but I always rock them first. That is, I tap downward, toward the center of the shaft, on one end of the key until it tilts. Then the adhesion between the shaft and key has been broken. I then tap longitudinally on the end of the key that is now raised well above the shaft, due to the tilting of the key. That is the right way to remove a Woodruff key, and the wrong way to remove a rectangular key, so you need to know which kind you have. Thanks Deejay.
