Do a full factory reset with sanitization
You can use the U.S. DoD 5220-22M 7-pass scheme to erase data from a sensor, and clear disk space.
About this task
Important: 
This procedure will cause the system to lose all its data and
                configurations. The networking configuration will be reset to factory
                settings.
Procedure
- Open a shell console.
- 
                Enter the command:
                n2os-fullfactoryreset -iknowwhatimdoingThe system reboots with a factory setup.
- Do the basic configuration again.