Look, man, if you haven't taken it apart, seriously consider just blowing it out with compressed air.
I find Nork rear sights to be a little finnicky when it comes to going back together without stripping something. I am always very careful with mine but a few guys I've heard from have stripped theirs without trying hard at all.
So BE CAREFUL! It's a funny sight IMO, and you don't want to be stuck searching for a replacement AFTER your rear sight breaks!
Get a fancy rear sight, THEN take the old one apart...or just leave it alone, and blow it out with air and wd40.
That's my recommendation, anyway.