I don' have a photo, but its easy. Run a wire from the DUI (12 ga) through the firewall and right behind the gauge cluster. Unscrew the gauge cluster, don't forget to remove the speedometer cable from the back of the cluster. Reach your hand behind the cluster and simply unscrew the speedo cable from the cluster. Try to pull the gauge cluster out as far as you can. Right above or behind the key ignition is the "pink wire". Very little of the pink is exposed so look hard, also the wire has a resistor cloth like wrap around it. Unplug the pink wire and take the new wire from the DUI an stick it in the female connection that the pink wire came out of. That's it.
You can do several searches on the "pink wire" and you will find a lot of info. Also Mustang Monthly did a blurb about the DUI and the pink wire.
Good luck and if you have any further question just ask.