Deleting Active Directory User
Follow the steps below to delete an Active Directory user:
Go to Settings > General > Users and Roles.
The Users and Roles page opens in the Users view. Hover over the Active Directory user you want to delete, and then click ellipsis icon in the rightmost cell of the row.
In the menu that opens, click Delete.
In the dialog box that opens, click Delete to confirm that you wish to delete the AD user.
The Active Directory user disappears from the list of users.