Back up your photos, contacts, files, and app data
Charge your phone to at least 50%
Open Settings
Tap System or General management
Tap Reset or Reset options
Tap Factory data reset
Review the items that will be erased
Tap Reset phone or Reset device
Enter your PIN, password, or pattern if prompted
Tap Erase everything or Delete all
Wait for the device to restart and complete the reset
Set up the phone again after it restarts