How do I re-washer this tap?

[sharpener]

... bought from B&Q maybe 10 years ago?

 

Needs a lot of turning to turn off completely so I would like to try rewashering it.

 

No visible grub screw. Can't prize any cap off the top to get at any fixings. Can't turn it on far enough to see any hex flat underneath to unscrew the headworks.

 

Any ideas?

[markc]

Small screwdriver to pop the caps out of the tops, remove screw to remove knob and you will then get to take the tap apart. 
just re read post and you cannot get caps out? If that’s right the whole cap/knob may be held with a snap ring and just pulls off …. With some force ….. or it may shatter!

Edited 2 hours ago by markc