replacing cartridge for Blanco mixer tap?

I have a leak from a Blancostrand BM/6075 mixer tap. How do I remove the chrome cartridge shield without damaging it?
Mike, January 2018


done
You do an Internet search. 30 seconds got me these:

https://www.youtube.com/watch?v=vbdQuzTV3BE

https://www.youtube.com/watch?v=lQ_6OdNK3CM

Two nicely produced videos

saabswg, January 2018