B Service on 98 ML320

Hello,

On my 98 ML320 with 74000 every time I start the engine I get a little tool with 2000 countdown. I called my dealer, he suggested B service. After finding out the B service is $350, I decided to do it myself. Is it hard? Is there anything special that is required to be done by the dealer? If not, and I can do this myself. How do I reset the FSS?

Thank you.