In order to hard reset a O2 Jet, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
O2 Jet device will be brought back to the default configuration of a brand new device.
1. Use Power button to turn on the phone.
2. Now open Menu and select Security Settings and Reset Factory Default.
3. Confirm. You will be asked for the security code. Provide it. Default code is 1234.
4. Lastly, select either Restore Default Settings or Delete All User Data. Your phone will reset & restart. Well done!