This is not just a drain tube. It has a one way rubber valve at the end that is VITAL for proper engine breathing. Without the tube and valve, the engine will not run as VW designed it - with slight negative case pressure.
The tube is swaged on to the filler top so there isn't an easy way to replace it. I suggest you get a decent s/h filler top and tube, unscrew the collar inside the filler to remove the old one (heat the collar forst with a hot air gun to soften the baked oil deposits) and fit the new one. Then make sure you fit a proper valve to the end - many of the repro valves have the end sealed so be sure to cut a slit in it with a blade before fitting it.