I just got a used Nikon 28mm 2.8D lens to use with my D600. I need to set the aperture on the lens to f22, but the aperture ring lock seems stuck in place. It will not budge. I don't want to force it too much and break it. Is there a way to fix this? Thanks.
The aperture ring lock only locks the aperture to minimum aperture (f/22 on this lens). If the lock is engaged, your ring will be at f/22 and will not be movable. If your aperture ring is on another aperture, chances are that the lock is not actually enabled, but rather, the mechanism is jammed. In this case, you'll need to have your lens professionally serviced.
I owned this lens for many years and its diaphragm jammed up with lubricant from inside the lens, so there's a decent chance that the same has happened to you. If the blades are jammed, the ring won't turn.