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 Site Indexes and Forms.
A new screen will appear. Click on the 
icon to the right of the index you wish to edit.
A new pop up will appear, edit the relevant information and click Edit Index.
If you are unable to follow these instructions, you may not have the required user permissions. Please contact your Site Administrator.