How to unassign a tag from a user who is not linked with any center

First check how to find a tag: https://myclay.freshdesk.com/a/solutions/articles/5000829085

In our case, the tag is assigned to a user, but without any center linked.

We need search the user by the name, look the example below: 

Then click Users, and search on the user name:

Go to the profile, and unassign the tag.