Don't do what i did!!
Removed fuel filter assembly on cdti and are lass said it looks like rain so put key in to turn ignition on to red lights to wind up the windows you guessed it!!
Fuel spurts out of the fittings all down the back of the engine it's soaked and stinks, 30 mins of cleaning up and it stinks a bit on the hot exhaust and engine but is clearing away.
Car runs smoother with new fuel filter & rest of filters and oil done.