all you need to do is turn your radio off. then turn off the clock by pressing the clock button only if the clock is on. then press either preset number 5 or 6(one of these will turn the demo mode on and the other will turn the display inverting thing on and off). when you press either button you should hear the unit beep. first try 5 and turn the radio on and see if that turns is off. if it turns on the demo mode(you will only know when the radio is off), go back and press the number 5 again with the radio off and press the number 6. hope this helps!