Turn the electricity to the oven off by turning the breaker to the off position. Open the cover to the wiring box on the back side of the oven.
Remove the screws from the connector (strain relief) and put the "wings" (the separations in the wire) into the access hole. Feed a wire in through the relief connector to the wiring box.
Secure the screws on the connector (strain relief). Snap the connector into place over the outer insulation of the wire.
Loosen terminal screws. Feed a wire underneath the assigned terminal and fasten it in place by tightening the screw again.
Connect the white wire to the middle terminal. Connect the black wire to either the left or right terminal and the red wire to the remaining terminal. Either wire can be connected to the left or right terminal as long as they are both connected.
Close the cover on the back side of the oven and slide the oven into place. Make sure to avoid damaging the power cord with the oven. Turn the electricity back on.