How to update a new unpaired Apple watch

Just purchased my first Apple Watch 3, and while following pairing instructions I was told that my iphone6 needed to be updated, and I did so. Then while pairing, my phone displayed that “Update Your Apple Watch”

“to finish pairing your Apple Watch must be running the latest version of watchOS”.

So... how do I update my new watch without it being paired?

I would appreciate any help that I can get.

thanks in advance.