I could tell you to read the owner's manual, or just guess what the light means (like every other douche on these boards does), but I will keep this post informative - because that is what these boards are for.
According to the owner's manual, the RED EXCLAMATION POINT INSIDE OF A RED TRIANGLE means that the car is past due for service. If you haven't completed service, you can take it in and they will turn it off for you when they service the car. If you do your own service, do the following to change the date:
1. Put the car in ACC mode (push start/stop twice)
2. Scroll through the BC options in the dash by using the rolling switch on the turn signal stalk.
3. Scroll through until you see SERVICE INFO by rolling up on the rolling switch
4. Push the BC button (also on the stalk). You should see a date that is past the current date.
5. Reset the date to whatever date you want (when ever you want to be reminded for service) by pushing and holding the BC button in until a square shows up around the month in the date. Use the rolling switch to change the month and then push the BC button to access the year. Roll through the years with the rolling switch and then hit the BC button to save.
2007 E92 335i / Montego Blue
/Black - European Delivery
2013 F10 550i / Alpine White/Cinnamon
2014 F10 M5 / Singapore Gray