Cut down into mortise:
Using a modified version of of the previous saw the cut is continued to the bottom of the mortise. This ensures that the button won't be damaged when the neck is removed.
When the saw cuts are judged to be deep enough, the neck will given short sharp blows to the side until it comes away from the body (this step is not for the faint hearted). If the neck joint was made well, some splinters of the top block will come away with the neck but, because of the careful preparatory sawing, the button and ribs are preserved intact