When you bring your iOS device to our shop, we ask you to erase it and turn of Find My iPhone (FMi) feature. It is because sometimes the repair concludes by swapping for a new or refurbished device. The best is to back up the device (using iCloud Backup, or a computer with iTunes), then turn off FMi with Settings > iCloud > Find My iPhone and the erase the whole device in Settings > General > Reset > Erase All Content and Settings.
If you cannot access the settings for some reason (broken screen, cellular and Wi-Fi not working, or the device doesn't start at all after ie. liquid damage), it is still possible to remove the device from your iCloud following these simple steps:
- Make sure the device is off or at least not on the internet (airplane mode)
- Log in to www.icloud.com using your Apple ID
- Click Find iPhone icon
- Select the device you want to remove
- Wait a few moments when the iCloud is locating the device. After a while, it will show it as Offline
- Click Remove from Account to disconnect this device from your Apple ID
When you're parting with your device - whether you're about to sell it, or give it to a friend - erase the phone completely via Settings. You will save yourself going through these steps after a disappointed call from the buyer or friend.