Clean bolt exterior with toothbrush and wipe. Every so often, flood interior and exterior with carb cleaner and blow dry with compressed air. Drop of oil (CLP) on ejector, extractor pivot and spring, and in firing pin hole. Wipe excess and re-install. Grease on lugs of bolt. Wipe off excess.
For winter, or very dusty conditions, use dry (graphite) lube.
Disassembly is seldom needed, unless and until you croak an extractor. At that point, you WILL want the special bolt assembly/disassembly tool. A good idea to have a spare extractor, ejector, and their springs always on hand. GI, of course.