If the contacts are corroded ,then it will need replacing.

Hard to tell without seeing it, maybe not even then, but the OP says the contacts "look" corroded.

If he can see the corrosion, he can clean it.

The real headaches come when you can't, like inside the steering column switch unit on my car, limping along with ocaissional sprays of contact cleaner.

OP, you might have to use some ingenuity/improvisation if the contacts are visible but hard to access.

I like aluminium as an abrasive. Maybe an aluminium roofing nail in some kind of tubular holder would get there? I use arrow shafts or bits of old TV aerials for this kind of thing, but you might not have them

Wooden BBQ (satay stylee) skewer, optionally with foil wrapped around it?

In the army we used matches and spit to clean residue of propellant from the awkward bits of rifles.If you need something more brutal you can burn the matchead first.

IF you get it cleaned up, apply some protectant (WD40, vaseline, silicon grease, etc) to stop it re-corroding.

You can buy contact-cleaner spray which MIGHT help but its fairly pricy, with no guarantee it'll work, so if it comes to that it might be better to just replace.