

Hello, I need to remove this bathroom mixer tap to replace the cartridge (or the while tap if it’s beyond help, yet to be determined) as it leaks. I removed the grub screw but the top will not budge. Any ideas? Tap brand in Unique. Google doesn’t offer any help. I’m pretty sure the tap is as old as the house, 18 years give or take.
Please ignore the painters tape. It’s to stop my children using the tap while I figure this out. Thank you.