On my Phone
Turn off Find My iPhone on the device
Step 1
Tap on Settings.

Step 2
Tap on your name at the top.
Step 3
Tap on Find My.

Step 4
Tap on Find My iPhone.
Then tap the toggle and type in your iCloud/AppleID Password to turn the setting off.
Step 5
Confirm that Find my Device is set to Off.
Here’s a video for you visual learners.
Congratulations!
Your device is no longer associated with Find My iPhone. We are now able to send your device in for service.
With iCloud.com
Turn off Find My Device with iCloud.com
Step 1
Visit iCloud.com

Step 2
If you have Two Factor Authentication on you may see this screen.
For quick access, select Find iPhone here:
