Sofia Monobloc Tap; how do you replace the ceramic valves or remove handles?

I have a tap kitchen tap which is made Damixa. I bought it 7 years ago from B&Q - same as this on here - see link:

http://www.diy.com/diy/jsp/bq/nav.jsp?action=detail&fh_secondid=9996593&fh_location=//catalog01/en_GB/categories%3C{9372014}/categories%3C{9372039}/categories%3C{9372150}/specificationsProductType=taps/specificationsSpecificProductType=1_tap_hole_taps

The tap is dripping on the cold side. Can you get replacement ceramic valves for these taps and are they easy to fit?

How do you get the handles/head gear off? On mine there is no Alan-key bolt on the handles to remove it.

I would appreciate and help or advice please.

Many thanks all

Michael
November 2011