All of your data in Samsung Omnia II will be remove，so make sure any additional installed apps or user data have been backed up before a hard reset.
After your Samsung Omnia II finish all backups, follow the steps below
1. From the main screen and choose the Start menu.
2. Select Settings in the menu list.
3. Then choose Memory Settings in the menu list.
4. You will see “Clear All Data” click and confirm Yes.
5. It will require enter the phone’s lock code.Usually,lock code maybe the last 4 digits of the phone’s number.
6. Choose Done,then the phone will reset.
7. Good luck.