To restore an iPhone from a backup, navigate to the iCloud menu of the phone settings and choose Manage Storage from the Storage menu. Choose a backup from the listed devices to begin the restore, and reboot the device once the process is complete.
Tap a device to check the date and size of the latest listed devices that are backed up. Select the option to reset the device under the General menu of the device settings, and choose Erase All Content and Settings when prompted. In the setup assistant that opens after the phone reboots, choose the option to restore the device from a backup. Sign into iCloud and choose the latest from the list of backups to begin the restore process for a device that is already backed up, or for a new iPhone.
To restore an iPhone from an iTunes backup, connect the phone to the computer on which the backup is stored. Open the latest version of iTunes and navigate to the list of connected devices. Choose to restore from backup to get a list of stored backups. Select the latest backup, click Restore, and wait for the process to finish. Wait for the iPhone to restart and sync with the computer to complete the restore process.