Should change the timing belt every 40k, tensioner every 80k. Belt is about ?10-?15 at vw, always get the genuine parts!
Line engine up to TDC
Remove alternator and power steering belts
Remove upper cover
Remove Crankshaft/ water pump/ power steering pulleys
Remove lower cover
Turn tensioner anti-clockwise
Remove timing belt
Check marks are still aligned
Fit new belt
Tension belt
Check belt tension, belt should turn 90 degrees on longest run
Rotate engine 360 degrees twice to check marks are still aligned
Re-check belt tension
Refit rest of stuff as removed
Hope that helps
