Hey Steve, first thing is make sure you haven't applied stain to the heel where it makes contact with the neck pocket. Glue works best on raw timber. If you have it will need to be carefully sanded off, be careful not to sand where it will be visible !
Mask around the bottom and edges of the neck pocket and ontop of the body where glue may squeeze out. I apply an even aount of glue in the pocket but not too much glue. Enough to give all contacting areas good coverage.
Clamp and leave for at least 24 hours. Get the titebond original (red label) glue