Trailer hitch/Towbar electrics help needed

[jaima]

Hi All,
2003 E53 3.0i auto
I bought a used towbar (photo) on Ebay it has a 13pin tow connector on it with the plug/wires still attached(photo), I also purchased a towing module (photo) as there isn't one in the X5 next the battery in the part where the cables are hidden
There is also a pre-fitted connector at rear of spare wheel (photo) what is this for?

Is there anything else that I need in the electric parts???
if anyone could tell me in layman's where to fit/connect the electric connections together I will truly appreciate the help and any information
Edit: is photo three for a type of PDC module and where is the PDC module??? or could I just switch off the PDC before I start driving ??
Stay safe guys