When the white cover and the ball motor have been removed, the 6 push buttons will be easily accessible. 3 of the buttons can be removed from their slots by gently pulling up on each. The other 3 buttons are located lower in the unit and are held in by 1 phillips screw each.

When reassembling ensure that the button is in the inner slot circled in the picture with the button, and shown by the arrows with the button removed.