Think they're all slightly different, but on my Passat there are two relevant resets, one for oil change, and one for service/inspection.
Can't remember the exact procedure, and one is slightly trickier than the other, but it's some combination of activating the hazard lights and keeping the trip odometer button pressed in when you push the ignition.
You then get a message on the MFD asking if you want to reset them (think on some of them you can do it more directly via a normal MFD procedure, but with mine it's not something that you'd ever guess without knowing the exact procedure, so a bit like these secret 'easter eggs' in a computer game or whatever).
But plenty of YouTube videos for this kind of thing, although for some reason I can never make out what the people are saying
But a bit better than the warning 'bong' and MFD message flashing up every time you want to move one place up the rank