A factory reset will restore your Samsung phone to its out-of-the-box settings.
Note: Factory resetting your phone will delete your personal data and settings — including contacts and photos. To prevent data loss, ensure you back-up your device before doing a factory reset.
From the home screen, swipe up to open the menu.
Tap Settings.
Tap General management.
Tap Reset.
Tap Factory data reset.
Tap Reset.
Tap Delete all.
Your device will automatically reset and reboot.
After your device has been reset, you might have to reconfigure certain settings, such as the date, time, and Wi-Fi.