Hard Reset SAMSUNG B7510 Galaxy Pro

First method:

1. Power off the phone.
   
2. Then hold and press 2 buttons: T key + Power button, until you see menu of Android Recovery Mode.
   
3. Now select option "wipe data/factory reset" using Volume button to scroll option, and Home button to confirm operation.
   
4. Next use Volume Down button to browse option "yes", and confirm it with Home button.
   
5. After that press Home button to accept option "reboot system now".
   
   
6. Success!

Second method:

1. Press the Power button, until your device is on.
2. Then from the home screen open Menu and choose Settings.
3. After that select Privacy and tap Factory data reset.
4. Choose Reset phone and select Erase everything to begin hard reset operation.
5. Good job!

WARNING !
Hard Reset will erase all of your data
All described operations you are doing at your own risk.