Hello I'm Paul and I will help you with an Answer to your Question
Unfortunately there is no manual reset procedure on this model
you need an Audi compatible scan tool to perform the reset
I am attaching the information and list of compatible scan tools below...
Let me know if you need more help
Am I correct that these scan tools are all in the hundreds or thousands of dollars?
Yes you are correct.
You can ask your oil change shop if they have the appropriate scan tool to reset your service reminder before bringing it in.
an oil change shop should have the tool to reset your reminder
Just verify they do before bringing it in or else find someone who can