Connect to Pixhawk

Does anyone know how to connect the Reach module to the pixhawk to provide the pixhawk with the position. I just want the solution output to go to the pixhawk. I am guessing that I would use the DF13 connector for serial communication and one of the serial ports on the pixhawk. But does anyone know which one would be best and what format the output should be in?

The corrections from the base station reach will come through wifi directly to the reach module.

Take a look at the reach documentation, it is well documented there.