Hard Reset ZTE Z730 Concord II

First method:

1. Press Power button, until your phone is on.
   
2. Then from the Home screen tap Menu key.
   
3. Scroll to System Settings -> Personal -> Backup and reset -> Factory data reset -> Reset phone -> Erase everything.
4. Done!

Second method:

1. Turn off your cell phone.
   
2. Next hold and press Volume Up + Home button + Power button.
   
3. Then from the menu choose option "wipe data/factory reset" using Volume buttons to navigate, and Power button to confirm operation.
4. Now select "Yes -- delete all user data".
5. After that confirm option "reboot system now".
6. Success!

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