How do you reset the service a indicator on a 2001 C180?

i purchased from eBay a reset coder that resets the srs )AIRBAG) error and the service light error it cost me £7.50 to purchase and £7.50 for delivery LOL so for £15 i had reset my airbag and my service light it took me less than 2 minutes to do so go buy the stuff you require then reset it

MUCH MUCH MUCH cheaper than maindealers with same results