Select Television on the main menu
Change channel with the channel knob. It will cycle through ...27, 28, 29, 30, AV, 1, 2, 3... etc
AV = AV-IN

Physically, you connect the AV cable to either the existing AV-IN socket (if fitted) on the centre console, visible from the rear seat.

If the socket is not fitted, you need to run the AV cables to the white connector on the video module, which is under the black plastic cover in the spare wheel / battery well in the trunk/boot.