In order to hard reset a Sonim XP7, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Sonim XP7 device will be brought back to the default configuration of a brand new device.
1. Turn off the phone by press-holding Power button.
2. Open Menu > Settings > Backup & Reset > Personal Settings.
4. Continue to Factory data reset > Reset Phone > Erase everything.
5. Phone will now reset'n'restart. Done.