I'd agree that Erwin will have everything that you would need to know as it is the official VW Group technical support documentation for workshops and anyone else that is not an official VW Group verified repair point.
I joined for SEAT stuff, then messed up and wasted my 60 minutes, so have not been back there, it will probably take a bit of getting used to and so after that initial training yourself period, be a valuable
resource.
I have a feeling that the later gearbox family might not have a drain plug, just a fill/level plug, there are some on line VW Group parts listings catalogues that you could search for and examine for availability of parts like draining and filling plugs and that would give you FOC ability to check up on this.
Edit:- the later 5 and 6 speed boxes are from the same family.
I've never ever, in 40+ years of owning cars, changed the gearbox oil, and I've owned cars that were kept from new to 13years and 105K miles - just my take on things like that.
