Check your owners manual.
It will say.
White Balt, bitch.
i've read....(although never tried because i have an LT)....that turning the key to the ON position, putting the car in neutral, pressing your gas pedal three times within 7 seconds, returning the car to park, and starting the engine works...
could be complete bs....but it never hurts to try...
if you have a LT model, There are two buttons to the right of the steering wheel, press both at the same time hold for a second, cycle through the option on your DIC until you get to oil life, press (i forget which button) to reset the cycle
My 08 LS XFE has 2 buttons on the wheel.^LS models are not equipped with those buttons. LT and up have them, the lowest of the low level cobalts (the LS) doesnt have it