Q7 caravan brakes

G'day To all the Brits from an Aussie

I have a 2011 Q7 3.0 tdi and it came with the towpac and it has a 13 pin euro plug I will be fitting a brake controller to it and that is the easy part . I can't find anyone in Australia that can tell me what pin the brakes will be on when it is all connected it has the plug under the steering wheel and the 2 pin plug in the boot area but nothing tells you where it comes to at the plug for the caravan brakes .

Here all the auto electricians want to do is replace the 13 pin for a 12 pin and want $1500 to do this I want to fit the 13 pin plug to the caravan and that is a twenty minute job so please help