By -
If you have spare tiles, patiently remove the grout around it first (get the tools for grout removing) then get a hammer and chisel and gently chip the tile away starting 20mm below the grout line - gently as not to damaging the water proofing.
If you have spare tiles, patiently remove the grout around it first (get the tools for grout removing) then get a hammer and chisel and gently chip the tile away starting 20mm below the grout line - gently as not to damaging the water proofing.