I have a 1994 Cat320. The head sink faucettes started to drip causing the pump to run. I have the replacement cartridges from GROHE, but can't see how to remove the taps. They are diferent from the GROHE model used in the galley, where you simply snap out a tab (hot or cold) and remove the screw holding the handle in place. The red and blue spots don't seem to be removeable on the head sink taps. I don't wwant to force anything. help please