How to reset watch

To unpair and erase watch and remove Activation Lock.

On a computer, go to iCloud.com and sign in with your Apple ID.

Go to Find Iphone.

Select All Devices, then click your Apple Watch.

Click Erase Apple Watch.

Select Next until the device is erased.

Click the remove button next to your Apple Watch.

See this;

How to pair your watch with a new phone

And start at the section "If you don't have your old iPhone or you erased it"

HI - I unpaired my watch before I erasing it. Now I am in no mans land. Can not pair it to my new iphone. Any ideas?