Back up your photos, contacts, messages, and files
Charge your phone to at least 50%
Remove your SIM card and SD card if needed
Open Settings
Tap General management or System
Tap Reset or Reset options
Tap Factory data reset or Erase all data
Review the warning
Tap Reset or Erase all data
Enter your PIN, password, or pattern if prompted
Confirm the reset
Wait for the phone to restart and erase all data
Set up the phone again after it restarts