1- unscrew the ‘H/C’ disc on top of the tap. This will expose a screw (some discs might pop off)
2- remove the screw
3- lift off the tap lever head. This exposes the brass nut on top of the ceramic cartridge
4- remove the nut which is part of the cartridge and so the cartridge will simply lift out
5- wipe the seating and seal with a clean cloth, smear the surfaces with vaseline and replace the cartridge
6- See this post for more on cartridges and maintenance: http://blog.grandtaps.co.uk/how-to-clean-ceramic-disc-cartridges-in-taps/
