Originally Posted by
chorlton
Don't forget that the fixed cup is likely to be reverse threaded. Prior to attacking it lay the frame on its side with the DS cup down and dribble some Dismantling Fluid, my side of the pond the brand name is PlusGas, in from the NDS. Leave it for a couple of hours or overnight and repeat. When you get around to removing the cup realise that you might have to be 'brutal'. Hold the tool in place with the flat of your palm and bang it with a hammer.
Unless the fixed cup is damaged beyond redemption or you intend to replace the entire bottom bracket, there's no compelling reason to remove the fixed cup. Clean it in place and repack with fresh balls and grease.