I bought an Apple Watch from Ebay and everything worked fine till today. Now I updated the software on my Apple Watch, and it asks for iCloud ID and Password. The message that appears on my iPhone's screen is: Activate Apple Watch. This Apple Watch is linked to an Apple ID. Enter the Apple ID and password that were used to set up this Apple Watch.

I tried to contact the owner on ebay, but he does not responded. I read about this method, but how to use it on Apple Watch? Is there any method to bypass Apple Watch iCloud activation lock? How to resolve this problem?
Please reply.