Hi
Activation Lock prevents unauthorised use of Apple Watch if it is lost or stolen.
It is not possible for a user to delete their Apple ID.
It may help to follow the instructions here:
If you still need assistance, ask your Dad to contact Apple Support for assistance (as the Apple Watch is locked to his account) or to make a Genius Bar reservation and accompany him there, taking along your Apple Watch and your original proof of purchase for it (also check with Apple in advance of the appointment to ensure that you each take along any other necessary documentation):
- Contact - Official Apple Support
- https://twitter.com/applesupport
- http://www.apple.com/retail/geniusbar/
There is no way around this security feature.
More information and instructions: