technically, they shouldn't use much. It really doesn't need to be glued at all if it fits as it should. But, they do put a little dab in there so it doesn't fall out when changing strings and such. Ya don't want too much though, because of maintenance, nut replacement, etc. Ya want it to be able to be removed without allot of trouble. That said, if it is in there snug as it should be, sometimes it goes slightly below the surface of the headstock or veneer, and of course it does on the fretboard, so ya want to be sure not to pry against that so as not to damage the neck, headstock or fretboard, But a swift, solid knock with a wood dowl or something in a perfect world should knock it out.