Having replaced the washer in one of our taps in our shower at home this
now makes us experts in the eyes of our friends who have called upon us
to help them do the same for their leaky shower tap.

However, the shower has 2 square taps, both of which have a stylish
little piece of granite glued on top of them. Am I correct in assuming
that this needs to be removed (it's going to take a hammer and a chisel
to do so) to get at the cap nut underneath to remove the tap? There
doesn't seem to be any other obvious way to remove the tap but maybe I'm
missing something.

So do I have to pry off that granite bit?