2. Press and hold the recovery buttons. The buttons vary from device to device, so you may need to look up the instructions for your particular phone. You will need to press and hold the buttons for a few seconds. Some of the more common button combinations include:
Volume Up + Home + Power
Volume Down + Power
Home + Power
If none of the above work, do a web search for your phone’s model plus “recovery mode” or hard reset.
3. Select Factory Reset. Once the recovery menu opens, you can navigate the menu with the volume buttons. You may need to open the Recovery menu to find the Factory Reset mode. Use the Power button, some models use the camera button, to select your menu options.
You will be asked to confirm the factory reset.
4 Wait for the restore process to compete. After your phone resets, it will be set back to factory defaults and will be like it just came out of the box
EDITED BY DrAcON