Apple watch
I forgot my Apple ID and can’t unpair my Apple Watch from my old phone
User profile for user:
Community User
If you forget your Apple Watch passcode
Or;
From a web browser,sign in to iCloud.com with your Apple ID.
Go to Find iPhone.
Click All Devices at the top of the screen.
Click your Apple Watch.
Click Erase [device]. Select Next until the device is erased.
Click Remove from Account.