WE Browning Hi-power lanyard fixing..

I would like to fix a lanyard mount to my WE Browning Hi-power.. I was speaking to someone at 'Corridor of Death' who had fitted one to theirs and who said it was really straighth forward apart from !!.... The problem is that after a few at the social that night, I can't remember who it was that I spoke to and what it was to watch out for.. Who ever it was at Corridor please PM me if you remember the conversation or for that matter any enlightened person who has fitted a lanyard mount to one of theirs.
Regards Chris