Press Applications and choose Admin Settings > Restart.
Resets any user and network setup changes that you have made, to the previously saved settings that the phone has not written to its flash memory. The phone then restarts.
Reset settings
To reset settings, press Applications and choose Admin Settings > Factory Reset.
Restores the phone configuration or settings to factory default.
User Guide
For information on how to operate your Cisco device not referenced here, please refer to the user guide.