This probably sounds stupid - but we just bought this car and there is no owners manual - we changed the oil and the light is still lit up. How do you turn off the change oil light? Thank You

You need an owner's manual and can get a free one in a pdf download here. http://www.devicemanuals.com/guide/Automobile/Oldsmobile/Oldsmobile-Alero-Owner's-Manual-1999-==TVRFd016QXk=.html
To reset the Change Oil light turn the ignition on but do not start the engine. Push the RESET button located in the driver's side instrument panel fuse block. The light will start to flash, press and hold the reset button again. The reset is complete when you hear the chimes sound and the CHANGE OIL light goes out.

TELL ME WHAT YEAR MODEL CAR TYPE.I WILL TELL YOU.THERE ARE TWO DIFFERENT WAYS TURN OFF OIL LIGHT NEED TO KNOW WHAT TYPE OF CAR YOU OWN.