@Raffaele T. - I took a look at this too and it doesn't look like this is possible through the GUI in the current release. Then I did another search within the support site and saw that this is an existing Enhancement Request/Product Idea.
Take a look at that Product Idea post, there is a SQL query that was posted that you can run and remove sections. Be careful removing out of the box reports as these are tied to the menu options and workflows in the CAS.
Best of luck, Mike