How do you set the clock on a GM Part No 15131157 auto radio?

To set the clock on a GM Part No 15131157 auto radio, first, turn on the radio. Then, press and hold the "Hour" button until the hour digits begin to blink; use the "Tune" dial or buttons to adjust the hour. Next, press the "Minute" button to have the minute digits blink, and again use the "Tune" dial or buttons to set the minutes. Finally, press the "Hour" button again to save the time.