I'm sorting out the supplementary bonding in my bathroom at the moment,
and understand that I need to connect the 4mm bonding cable to the CPC
of the shaver-light.

To be strictly kosher, how should that be achieved in practice? The
shaver-light is wired from a junction box on the upstairs lighting
circuit, but clearly the terminals aren't big enough to take the 4mm
cable. I imagine that if I used a choc-box affair instead, with big
enough terminals, these wouldn't grip the small 1mm wires of the
lighting cable. Is it allowed to cut off a couple of strands of the
bonding cable so it fits into the jcb terminal? That sounds decidedly
dodgy to me - but if not, what's the correct way?

Thanks
David