I Think its a main dealer job only as they use a guided function with the Audi VAS computer to reset the service display
You will need to take the 2006 Audi A6 to a mechanic to have the service light properly reset. In some cases, a person can undo the battery to reset the light.
with a dignostic tool
Indicator lights on an Audi can be reset by a mechanic. The cars manual will also give instructions on how to reset this light as well.
Click the link.
A combination of pulling and pushing the 2 speedo buttons at the same time. This should reset the service light.
use a service rest tool or go to menu find service reset (be stationary lol)
To reset the "Service" light in Audi TT: With the car turned off Hold the right button on the instrument cluster Turn the key to the on position Push the left button on the instrument cluster Until the Service light goes out. (will say "Service in 10000 miles")
Resetting an 2008 Audi A3 TDI service light can be done two ways. One by addressing the problem and the other way is to unhook the battery cables for up to a minute.
2009 models can be reset using the centre display panel going to "car-settings" and just scrolling down, it will not alter the long life service, for that you need a scanning tool.
by going to an AutoZone store and having them reset it with their handheld computer system that plugs directly into the information port under the dashboard on the drivers side
The service indicator on an Audi A6 can only be reset with something called the VAGCOM. One may be found on line but it would be better to take in into an Audi dealership or authorized mechanic because more damage can be caused.
You need VAGCOM software to do so.