how to reset a 2013 s550 4matic maintenance message

Hello, there is a printed procedure in the Mercedes shop manual that we can't really reprint here, as it is proprietary information with a copyright. (Not to mention it's a detailed procedure that would be difficult to describe without the accompanying diagrams.) Your local Mercedes qualified technician would have this information, as well as most shops near you that have shop manual subscriptions. You could also subscribe personally at www.alldatadiy.com for one example.