The tow bar should be obvious, the electrics are simple to do, look on www.towingandtrailers.co.uk
There is a excellent simple top follow piccies there, but if you get stuck pm me.
One thing you need also is a audible indicator(buzzer) but again these are easy to do.
When you connect up the earth wire(white) don't put it into the ford loom, but onto a CLEAN part of the cars body(inside), if you need to power trailer/caravan batteries then you will need a 12S(S=Supplementary) socket also, again straightforward to do.
The standard or Normal socket is the 12N and black in colour, whereas the 12S is grey, or has a grey cover to distinguish it, pins are different so can't be accidentally plugged in wrong either.
If you can solder, this would be best for the connections into the rear light loom, but you will need to pass two wires to the other side to pick up the tailight and indicator on that side, scotchlocks are best avoided for reliability.
tabetha