I just have had the same problem, when i prized of the red coloured insert in the tap head & i was surprised to find no screw was no screw but there appeared to be a clip of some sort that lay on the top of the spindle
I simply pulled to the head upwards to remove it
mind you it took a wee bit of tugging to get it moving
changed the washer replaced the head job done
superscot
January 2011