Buy a draper tool off Ebay for your model... Or...
If it has the round connection under the hood the you need to find pin 19(Ground) and connect it to pin 7, this is service reset... Connect these terminals together for about 5-10 secs. You will need the ignition on but not started !!
BMW 2001 to current
Ignition Off (Position 0)
Press and Hold the trip odometer button while turning key to position 1 (ACCESSORY)
Keep the button depressed (about 5 secs.) until you see "Oil Service" or "Inspection" with "Reset" or "Re" in the display*
Press the button again and hold for approx. 5 secs. until "Reset" or "Re" flashes
While the display is flashing, briefly press the button again to reset the Service Interval. After the display has shown the new interval you should see "END SIA" for about 2 seconds