I've tidied and polished a four arm LX m569 crankset and managed to get the outer ring off - using the unsubtle method of a mallet and a large old screwdriver... I'm now unable to get the crown nut tight enough to eliminate ring wobble - fortunately I managed to avoid butchering the nut. Anyone have the correct tool, or a picture of one, so I can get one ? Help will be much appreciated.