I wanted to change a washer on a kitchen mixer tap that is dripping, cold tap, but I cannot get the handle off. The hot side comes off fine. We have had to twist the tap quite hard for some time in order to try and reduce the drip. Have tried gently to lever it from the bottom but did not like to force it too hard. Also sprayed some silicone sray in but still no joy. I have had the handle off in the past to clean the muck that seems to accumulate inside. The tap is 22 yrs old. Anybody any ideas how I can get the handle off?