Reset device

Perform a soft, factory, and alternate master reset of the device.

INSTRUCTIONS & INFO

To perform a soft reset, press and hold the Power button.
Tap Restart.
Tap Restart again.
A master 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. This process cannot be reversed. 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.
To perform a factory data reset "Master reset", swipe down from the top of the screen with two fingers.
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 turning the device off.
Press and hold the Volume Down and Power/Lock buttons at the same time.
Press the Volume Down button, until "reboot to bootloader" is highlighted, then press the Power/Lock button.
Press the Volume Down button, until "BOOT TO RECOVERY MODE" is highlighted, then press the Power/Lock button. The screen will go black, wait until you see the phone icon with red triangle/exclamation point, then quickly press and release the Power/Lock and Volume Up buttons together to open the recovery mode menu.
Press the Volume Down button, until "wipe data/factory reset" is highlighted, then press the Power/Lock button.
Press the Volume Down button, until "Yes -- delete all user data" is highlighted, then press the Power/Lock button.