Navigate to the "Manage Users" page and find the user you'd like to remove. On the right side of the screen, there is an "X" icon that will let you delete the user. This will remove the user's access to Fidesic, and you will no longer be billed for them.
If you ever need to reactivate a user that was deleted, from the "Manage Users" page select "Options > Inactive Users". This will load a list of any inactive users, with the option to reactivate the user on the right side of the screen. This will allow the user to log back in with the same email address and password they used at the time they were deactivated.
If the user is not sure of their password after having their account reactivated, they can reset their password from the following link: Click here