Make the button
To attach the switch to the nut I used super glue to glue it in. If you do this, be careful that you don't get any glue on the button itself, or you won't be able to press it in anymore.
Then I attached a wire to one lead of the switch, which would go to the positive battery terminal. To make sure that the switch stays, in place, I jammed in a small piece of cork (wood or plastic would work just as well).