It was always the intention that the Discover American Studies CD could be modified. Academics and others involved in student recuitment could add in their own slides, delete slides, add logos etc. in order to promote their own American Studies courses.
However, in practice you do need to be able to find the files in the first place to be able to modify them. Today I set up a youtube account and made a video using BB Flashback Express recorder (a screen recorder which is available for free download) in order to show how to access the powerpoint files so they can be modified.