Bought a used 2001 E320 some months ago and just took it to Jiffy Lube for the first oil change. I asked them first if they could roll back the instrument panel service notification and they said no, it has to be done by the dealer. We're talking about $400 for an oil change and fluids service at the dealer.
So I took it to a popular MBZ service shop and to my surprise and delight they knew how to re-set the service notification just by pressing buttons on the dashboard.
I bet most of you guys on this ng knew this already, but for the few (like me) who didn't, think twice about paying dealer rates for routine service.