take a small propane torch to it. powder will fall off so easy and clean with no mess to clean up. just don't overheat the part or you could damage it.. just a bit over 400* usually breaks the bond.
i use jabsco to remove all the old poweder coating off of parts . i put it on and let it sit for a few mins then i usaly peel it off( wear kitchen cleaning gloves the stuff burns) and wiht a hose it cleans up pretty good it s the best way to take it off short of paying some one to do it.
never tryed the torch thing.