Once she receives the zipped file, she can save it somewhere (desktop, maybe).
Then highlight the zipped file and right click. There should be an option to extract files to. If she has her unit attached to the computer, Windows will assign her unit as a removable drive and give it a letter (like F:\ for example but not necessarily that letter).
So, she can highlight the file, right click, extract files TO, and browse to F:\voices\