Learn how to perform a soft and factory reset of the device.
INSTRUCTIONS & INFO
From the home screen, swipe down from the Notification bar. Note: A factory reset reverts the device back to factory settings. It will permanently erase all personal data, preferences, settings and content such as pictures, ringtones and apps that are saved to the device. Data stored to an SD card will not be erased unless otherwise selected. It is recommended that you save (backup) important data to your SIM, SD card, or a computer before proceeding.
Tap the Settings icon.
Scroll to, then tap Backup & reset.
Tap Reset phone.
Tap OK.
Tap OK.
If unable to reset the device using the above steps, try the Alternate master reset method by first powering the device off.
Alternate master reset method: With the device powered off, press and hold the Volume-down key, and then press and hold the Power/Lock key > Wait for the screen with the three Android images to appear, and then release the Power/Lock and Volume-down keys > Press the Volume-down key, until 'FACTORY RESET' is highlighted > Press the Power/Lock key.