Single Lever Kitchen Mixer Tap dripping - what to do?

[Bevy]

I have a single lever kitchen mixer tap, hot water is from a boiler that heats up when tap is turned on, the make on it is Spanish....and i cant see any screws on the tap itself. Its leaking from the part that swivels around and going around the base of the tap.
Please can you tell me how to get into the tap or a schematic/plans for such a tap? and how to stop the leak. The kitchen was replaced about 4 years ago by the previous owners...
Thank you

 

[EliteHeat]

You can probably pull the spouty thing out and replace the "o" ring. There is often a grub screw holding it in place, but equally often there is not.