See the two teeth on the liquor key?  See the two indentations on the grey packaging?  Set the teeth on top of the identations, then slide the button over.

There is also a newer kind where the button is on the hinge side and might not have indentations.  It works about the same way.  Slide the key along the hinge side, and you will feel it grab internal magnets.  Keep sliding it, and use the key to slide the button over.