Hello Vo,
There are two ways to reset the unit to factory defaults.
To revert to factory default configuration using the hardware reset button on the bottom of the unit:
1. Remove power from the AP
2. Using a paper clip, press and hold the reset button on the back of the unit. The reset button is located on the serial label, below the words "part number"
3. Apply power by connecting a PoE source
4. The amber LED will blink slow three times
5. When ithe Amber LED blinks fast, release the button
6. The AP will continue to boot in its default configuration state
From the webUI, navigate to the Operations main menu.Select Reset (factory default) from the menu at the bottom of the page. Click Execute
Regards,