Lo all how do I pop the rotor arm out off the dizzy assembly?

Also there is scoring on the plastic inside the red cap? What would cause this?

I'm going to replace the cap and rotor arm anyway

Should I stick with Bosch or use oe equilivant such as QH?

 

Sorry on the phone - damn predictive text

 

Rotor arm just pulls off mate, I used to use whatever Halfords had on the shelf.

 

sorted Karlos - cheers