This shouldn't be too tricky. You can write a very basic HTML file that comprises a list of links to the other files and place it in the uppermost level of the passworded area. Provide him with the password and the URL of this file, then he can right-click on the links to save the files. I think that would be the best way, since you probably don't want to move these files into an open folder.
I can't say with 101% certainty without knowing more about the nature of your password system, and that isn't one of my specialisms, but I think that should work.
Please ask if you need to know how to compose the HTML and links.