Mg z optical sight illumination light

[DAI]

Hello fellow collectors
I would like to ask if any one has ever taken apart a MG Z illumination lamp the lamp i have has a worn outer wire cover
{ shown in photos} i would like to make the cable look better by re attaching it however i cannot for the life of me get the light apart i was able to remove small screw but this was no help i have tried to turn the knurl grip put this will not move i do not wish to damage the lamp by holding it in a vice if any one can help that would be great
best wishes
DAI