We recently bought new taps for the bathroom as the old ones leaked and are years old 15+ would be my guess. I have managed to undo the back nut that seemed to have been fixed on with adhesive of some kind(which was a long task in itself), then I think yes I can finally fit the new tap at last and then I find the tap won't come off the basin I thought as the tap has been on for years it probably just needs some WD40 and a couple of knocks with a hammer from underneath, but it's still not budgeing. I'm starting to think it is set on a bed of adhesive. How can I remove the tap without damaging the basin? Thank you.