You can easy Hard Reset you Samsung phone by keys or buttons
- Turn off the smartphone
- Press and hold the “Power“, “Home” and “Volume Up” buttons at the same time
- After the phone vibrates, release the “Power” key but keep pressing the other two
- At the “Android System Recovery” screen, release all buttons
- In the next step select from recovery menu “wipe data / factory reset” using Volume buttons to navigate and Home button to confirm.
- In the next Screen Choose “Yes — delete all user data” using Volume buttons to navigate and Home button to confirm.
- After that select from recovery menu “reboot system now“.
All done wait your phone reboot.