I am trying to program a sears craftsman remote garage door opener. Where is the button on the back of the garage door opener power unit that I need to press in order to program the remote?

If it's not too old it will have a yellow, gray, red, or purple button either on the back or the side depending on the model. If it's an older unit it will have dips switches not a button and requires a remote with dip switches as well.