Hey Geoff,
i think the main problem is a lack of access to the rear of the lights. Fabricating a tool sounds like a good idea :)
i don't think you can lubricate the back of the lights due to the nature of the electrics.
Iv found this video, it may help :)
iv been unable to find any pics of the headlight bulb holder, sorry.
Hope iv helped :)
cheers
steve