I have lost my Apple watch. How can I delete it remotely?
How can I delete my Apple Watch that is lost?
User profile for user:
Community User
If it's online then;
To unpair and erase watch and remove Activation Lock
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.
Also this;