In order to hard reset a Docomo F-05B, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Docomo F-05B device will be brought back to the default configuration of a brand new device.
1. First of all, press-hold Power until the phone turns on.
2. Now open Menu and enter Settings.
3. Afterwards select Reset > Master Reset > Yes.
4. Lastly, type in the safety code: 1234.