Turn off the phone
Press and hold the correct hardware key combination for your model to enter Recovery Mode
Connect the phone to a computer if your model requires it to access Recovery Mode
Use the volume buttons to highlight Wipe data/factory reset
Press the Power button to select it
Confirm the reset by selecting Factory data reset or Yes
Wait for the reset to complete
Select Reboot system now
If prompted after reset, sign in with the previously synced Google or Samsung account
If you cannot access Recovery Mode, contact Samsung Support or your carrier