I used a tool off ebay, tubing with metal connectors on either end, one went onto the bottle of oil, the other screwing into the drain/fill hole in the gearbox.
When I finished filling it still I managed to cover my hands, arms and floor in oil.
Fluid coming out was darker then that i put in. It's been 20k miles and 18 months since the last change and the gearchange is noticeably smoother now. VW say the service interval is 40k miles, hmm.