The rings on j-spec lights are not replacable as the inside of the light is all from one mould. Not sure if this is the case with facelift ones though!
I've just done a set, and used some chrome effect aerosol paint to mask out and spray the rings. If you want to give them the facelift look, you can wet flat the whole unit with 600 grit or so, then spray the whole thing matt black. Then when it's gone off, carefully mask the rest of the light out and spray the rings chrome.
Some of the original chrome came away when removing the masking tape on one of mine, so it had to be re-done. So ba carefull
Edit: Just realised yours are facelift! Sorry, i'm off work with arc eye! Handy info for anyone else though.