If you have a Mercedes B246 which is the 2nd generation B-class then this page will show you how to reset the service indicator on a Mercedes B-class W246. Please follow the instructions below.
Turn the ignitions to position 1.
Press the mileage reset button twice
Hopefully this will display your cars serial number.
You should now be able to use the menu buttons on the steering wheel to scroll through the menus into the Assyst menu
There should be an option for Service Confirmation.
Please note this could invalidate you warranty.This information is provided for reference only and you use this knowledge at your own risk. I take no responsibility for any consequences arising from its use.
Information imparted on me by a friendly tech.