To connect the pump, take the white female connector on the pump and press the silver lever down so that the round opening is clear and not blocked by the metal lever.
Push the female connector onto the white male connector on the valve until you hear a "click".  It is important you push far enough to hear the click or the pump will not be fully connected even though it may appear to be connected.
To release the pump, push down on the silver lever and pull the female connector off the band.  If you need to release air during use, or re-pump the band, always deflated the band by pressing in the tip of the male connector on the band.
TIP: if the female connector is difficult to slide onto the male, it may help to touch some vegetable oil with your fingers and rub over the male connector on the bands to lubricate it.