Hi all, I have a leak coming from a bathroom tap. It's coming through the lever - I've circled where the leak is in red in the attached photo. I can't work out how to access this part of the tap or what I should be replacing. There is a small grub screw that you can also see in the photo, but this just allows the spout to be removed... and doesn't reveal any more clues about how I fix the leak. Any advice would be appreciated!