In fact only one wire, the signal wire, is needed if you are going to power the gimbal from the main flight battery e.g. If you solder the connections for he gimbal's power to the mainboard in the Phantom. If you intend to power the gimbal from a separate power source you will also need to use the ground connection. The middle wire, +5Volt, needs to be removed as the low voltage devices on the gimbal are already powered via a 5Volt regulator on the gimbal's control board.
On my gimbal, and all others I've seen, the servo pins are in reverse order to the inputs of the Naza FC. The top pin on the gimbal, the signal pin, corresponds to the bottom pin of F2, vice versa for the ground pin (again if using a separate power source for the gimbal).
Once connected you will need to enable the gimbal function in the Naza Flight Assistant Software, this is under the "Advanced" Tab and sub-tab of "Gimbal". Here there is a small button to click so that the gimbal will respond to the movement of the lever on your transmitter.
QUICK EDIT. I NOTICED ON THE SCAN DOCUMENT AN ERROR. IT CLAIMS THE TOP PIN OF F2 IS THE SIGNAL PIN. THIS IS INCORRECT AND IT'S ACTUALY THE BOTTOM PIN OF F2. THE TOP PIN IS GROUND OR -ve WITH RESPECT TO THE MIDDLE 5VOLT PIN.
Regards
Nidge