Does your car still have the owner's manual? The instructions are printed in there somewhere. I found it one time in the index in the back of the manual when my light came on. I had to hit the reset button after adding air to the tire that was low on air due to a nail in the tread area.
On the passenger side of the car, find the fuse box on the side of the instrument panel. You'll have to open the door to see it. Carefully pull the cover off because it's flimsy plastic. Do you see the red reset button? Now turn the ignition key to the ON position. Press and hold the Reset button for five seconds. This should cause your low tire pressure light to flash three times. After starting the engine, your light shouldn't stay on anymore.
