As your Apple Watch is currently displaying the message "Bring iPhone near Apple Watch", it has already been unpaired successfully.
There is no need to follow the instructions that are shown on your iPhone.
I had this similar problem. But the problem is not the watch contents or following the instructions.
The problem is that my iPhone has not saved a backup of the watch, so I have lost everything. Configuration, faces, etc.
I was switching from an Apple Watch series 0 to a new series 3.
Bad Apple! In the past this things weren't happening with you. You were my time saver, but nowadays you are as time consumer as others... You have to go back to the way where everything works seamlessly with no errors at first attemp.
Question: fixing unpairing watch error and watch says put phone near watch but I want to mess it up please help?