Anyone know if you remove just the plastic/glass or the chrome ring when replacing a bulb ?

No the whole housing needs to come off, flip the cover down nearest the rear of the car and you will find a couple of (torx IIRC) screws in there remove these and from memory the unit then clips out.

Thanks. Do you mean the sunglasses holder or the flat panel just in front of it ?

The flat panel just infront of it, it hinges down, so use something plastic (credit card etc) in the edge by the sunglasses holder to release the clips

Thanks. Sussed it out now. Led bulbs fitted.