You must deactivate Find My iPhone on your iOS device before returning your device.
Before returning your iOS device, be that an iPhone, iPad or Apple Watch, you must deactivate Find My iPhone and erase your content and settings.
When you erase your content, Find My iPhone and Activation Lock are also turned off. This must be done to transfer the ownership of your device back to EE.
If Find My iPhone is not removed this can slow down the return or refund process and could mean you get charged for the device.
go to Settings
tap General
tap Reset
tap Erase All Content and Settings
open the Apple Watch app on your iPhone
tap My Watch
tap your Apple Watch at the top of the screen
tap Unpair Apple Watch
sign in with your Apple ID
select your device and then Erase Phone
If you've already returned your device to EE, you can remove Find My iPhone remotely from your computer:
sign in with your Apple ID
select All Devices and find the device you wish to remove (this will show as Offline)
select the device and then Remove From Account