Remove power from your Guardian Keypad by disconnecting the power terminal block. Grasp firmly on the black plastic of the terminal block and pull towards you. It will disconnect much like pulling apart a Lego. The display on the keypad should be black and all LED lights turned off.
Remove the original credit card reader holder located in the front housing. There are four small phillips screws that need to be removed.
Install the new credit card reader holder in the housing and re-secure the screws.
Locate the Mag Stripe pins on the keypad circuitry. Attach the connector to these pins making sure that the connector is in between the 1st pin and last pin.
Make sure the red wire is on the left.
Plug the power terminal block back in and close the keypad up. Test the card reader by sliding any credit card face up in the swiper. The card will not be charged but the keypad should beep and give an Access Denied message.