How to reset Phone (1) to factory settings?

Before the hard reset, please back up any critical data as the factory reset deletes all photos and resets all settings.
1. Go to Settings>System>Reset options, and choose an option you want for factory data reset:
Reset Wi-Fi, Bluetooth & Mobile
This option will reset your smartphone's Wi-Fi, Bluetooth, and mobile network settings.

Reset app preferences:
This option will reset all phone app preferences without deleting any app data.

Erase All Data
Clear all data, including photos and music.