How to unpair my Apple Watch that was lost in another state
Watch was lost in Floirida. It is not charged. I am now in Pennsylvania. How do I erase all the data on my watch & unpair from iPhone?
Apple Watch, watchOS 4
With a web browser, go to: https://www.iCloud.com and sign in with your Apple ID. Open Find My iPhone and select All Devices (at the top). Then click your Apple Watch, select 'Erase Apple Watch', and select Next until the device is erased. Finally click "X" next to remove your Apple Watch. This would allow anyone who finds your watch to set it up as a new "factory fresh" watch and be able to use it as their own (without any of your data).
But I suggest you simply put it in Lost Mode. See the 'Put your Apple Watch in Lost Mode' section in:
If your Apple Watch is lost or stolen - Apple Support
If you already set up Find My on your paired iPhone, it's automatically set up on your Apple Watch and any Apple Watch paired using Family Setup.
So if your watch is lost or stolen, you can use Find My to help you find it again. And thanks to Activation Lock, your Apple ID and password are required before anyone can erase your Apple Watch and use it with their iPhone.
You can have multiple watches paired to a single iPhone but not the other way around.