To remove a user from an existing role

1. From the Home page, choose Security
2. Click on the Roles tab    
3. Using the search window find the role that you wish to view and select it in the grid
4. Click the Users in this Role tab
5. Select the User that you want to remove from the selected role
6. Click the Remove User button from the bottom toolbar
7. You will be prompted if you are sure you want to remove the user from this role, click Yes