I did it without any tubes. Undo the filler plug and put the VW gearbox oil in, it has a pull out nozzle which you can place in the filler then squeeze out the oil. It takes 2.3l IIRC.
My box is whining, I think it's diff bearings. Driving me mad at the moment. I can't get a smooth shift at all and the clutch snatches like mad. Terrible.