Glovebox light

Hiya

My glovebox light used to have a mind of its own (came on sometimes, other times didnt), but now it doesnt seem to come on ever. I guess it's a simple job of cleaning the metal surfaces, but getting to those surfaces is another story. Is there any 'proper' way to dissemble it? Has anyone done this before?

Here's a picture, although it's absolutely shocking... might give you an idea.