dome light question

[Dutch]

A stupid little problem.

I had no juice to the dome or cargo lite. Found some spots in the orange (hot) leads where while there was no visible break in the wire they were actually corroded right off in the insulation. Fixed that and now have cargo working. The dome lite works by turning it on with the light switch but opening either door does not. I'm guessing maybe the switches are bad, but neither of them working makes me wonder if it could be something else.

Any thoughts? If it is the switches, how do you get at them to replace them?

Thanks!