A factory reset will restore your phone to the settings that were configured in the factory. All of your personal data from the internal device storage, including account information, the system and application settings, and any downloaded applications will be erased.
Important: Back up your personal data before performing a factory reset.
Backing up personal settings
1. On the Settings screen, tap System > Backup.
2. Slide the Back up to Google Drive switch to the right.
3. Tap Back up now
Factory resetting the device
1. On the Settings screen, tap System > Advanced > Reset options > Erase all data (factory reset).
2. When prompted, tap RESET PHONE, and then tap ERASE EVERYTHING. The device will reset to the original factory settings, and then restart.