You don't want to try and pry it off with anything hard or metal as you will likely damage the finish.

What I do in this situation is use a flat shoe lace. Slide the shoe lace under the base of the knob then apply an upward pressure holding the shoe lace with your hands either side of the knob against the body, sort of fist-like (it's hard to describe in words!).
You're not so much pulling the lace, but lifting it, using the bottom of your fists as the fulcrum point.

Make any sense at all????