Thanks for the answer.

Opening those screws seems logical yes, but too bad there are screws with *philips* head cause they are so rusted that it's impossible to get them out in one piece. Tried driving them out with force and now screw heads are round shaped (hexagonal bolts would have been alot better idea).

Dont want to breake those screws either, so i guess I'll add grease were possible, clean contacts, mount it back and use it as long as it still works.