A factory reset will erase all data from your device and is irreversible. This is good to do if you are going to trade in or sell your device. It will wipe all of your personal information from the device.
From the Home screen, drag down the Notification panel.
Drag down the Quick settings panel.
Tap the Settings icon.
Scroll to System.
Tap Reset options.
Tap Erase all data (factory reset).
Tap Delete all data.
Note: Before you proceed, make sure to back up all photos, videos, and data you'd like to keep. When you factory reset your device, all your files will be deleted.