From the xCenta Dashboard, click on Tools > Admin in the top right of the screen. 



A new screen will appear. From the Administration screen, click on Manage Roles.




A new page will appear, choose the relevant role.


Scroll down to the bottom of the page and click Delete.



A new pop up will appear, click OK



If you are unable to follow these instructions, you may not have the required user permissions. Please contact your Site Administrator.