Watch became unpaired from the phone. Now the watch shows wrong passcode, which needs to be changed on the phone. However, since the watch is no longer paired with the phone, I can't get the option available to change the passcode. Help please!

I have a watch which has become unpaired with the iPhone it was setup with. It is locked with a passcode and the face of the watch states "Wrong Passcode" and that I need to open the Apple Watch App on my phone to re-enable the passcode entry and try again. However, the iphone stated the phone has become unpaired with the watch, so I can't do anything, There are no options for me to change the passcode and I can't pair the watch with the phone since it's locked. This is my boss's phone...Please Help!