N.B. Once you have the main lens off, you don't actually need to remove the whole assembly to get to the bulbs. You can pull the little diffusers off and then just pull the bulbs out. I took the whole thing out as I had a faulty connection too, and to be honest I think I would prefer to remove the 2 screws that hold in the whole assembly and replace the bulbs from the back of the unit, rather than risk snapping the little diffusers!

Bulbs are code number 501 sidelight bulbs.

Regards.