Hard Reset SAMSUNG T959v

1. First power off the phone.
   
2. Then press and hold together: Volume Up + Volume Down + Power button.
   
3. If you see text "Vibrant" (this is model of your phone), then release only Power button.
4. Now when you see yellow text, then release rest buttons.
5. Browse to option "wipe data/factory reset" with Volume buttons, and use Power button to confirm operations.
   
6. Next accept previous operation -> scroll to "yes", and accept.
   
7. After that press Power button, to confirm option "reboot system now".
   

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