There may be certain capabilities on the self-service portal that you do not want to display to customers.
This article describes how to modify the navigation menu elements on the self-service portal
Open ‘Advanced Find’ and look for ‘Web Links’ entity with the below criteria:
This should give you the list of all Primary Navigation items available on the Portal (as below)
Select the particular record and click on ‘Deactivate’ button on the Ribbon
Refresh the Portal page
Once you deactivate the navigation menu it will no longer appear on the menu.