like Sgt. said, unsolder the wires, but make sure you dont leave solder residue holding the star to the wires, use a desoldering wick.
if the star is glued, then heat the head with a blow dryer, until the head is too hot to touch, then put something that makes lever and lift. with little to medium force it should come out. dont force too hard.
there should be some residue of the thermal adhesive there, that conducts heat and electrically isolates the star, if you are to change the star you should repeat this process (reapply the thermal adhesive, thus isolating the star bottom, but making it conduct heat)