Ciaran, do any of your windows work? first thing i would check for is dud window switches
if one window works, then take the switch out and swap it around to see if both switches work
if both switches work then proceed to step 2

dismantle the door card, pretty easy to do, 4 screws on the card & two on the door handle
you'll probably need to take away the rubber membrane to get at the motor (good idea to replace these also when the cards are off)
check the connections to the motor, if you have a multimeter check that there is power getting to the motor itself
next step. while tapping the broken motor with a hammer try operating the switch, they sometimes just stick due to lack of use, and a couple of knocks free's them up
still dont work? then it must be banjo'd - get a replacment motor - u need the full assembly including runners - from a late spec golf i.e. not qtr panels
ring round VW breakers and get prices of them, you can get them for ?25
peice of pish to fit, 3 bolts on the motor, 4 on the runner, and 2 holding the glass to the runner