Motorola’s instructions explain that for a successful installation, the battery in your phone should be at least 50% charged and your device should be connected to a Wi-Fi network or LTE.
Motorola has already updated the Moto Z family to Android 7.0 Nougat. While this update would have been more exciting if it had brought Nougat 7.1.1, which is already available for Google's Pixel and Nexus devices.
If you haven't got the notification of this new software update yet, Just go to Software updates menu in Settings, and It will automatically start downloading the latest update. The update will take around 10-15 minutes to get Installed on your device.
Source: Google+ | Via: Motorola-Fans