In order to hard reset a Sonim XP6, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Sonim XP6 device will be brought back to the default configuration of a brand new device.
1. Switch off the device.
2. Open Menu and go to Settings, Backup & Reset, Personal Settings.
3. Continue to Factory data reset, Reset Phone, Erase everything.
4. Done! Phone will now reset'n'restart.