Returning an iOS Device (iPhone or iPad) to PBS

To return an iOS Device (iPhone or iPad) to PBS, please follow these steps:

If you paired an Apple Watch with your iPhone, unpair your Apple Watch.
Back up your device (Optional)

Go to Settings > [your name], and tap iCloud.
Tap iCloud Backup.
Tap Back Up Now. Stay connected to your Wi-Fi network until the process completes.

Sign out of iCloud and the iTunes & App Store.

If you're using iOS 10.3 or later, tap Settings > [your name]. Scroll down and tap Sign Out. Enter your Apple ID password and tap Turn Off.
If you're using iOS 10.2 or earlier, tap Settings > iCloud > Sign Out.

Tap Sign Out again, then tap Delete from My [device] and enter your Apple ID password. Then go to Settings > iTunes & App Store > Apple ID > Sign Out.