SanDisk Clip Sport Firmware 1.22 released

It says to "copy hex file to player’s root directory’’ – not sure what a “hex file” is, I guess it’s the download, but I do not have a “Root directory” on my Clip Sport.  I have “Audible”, “Audiobooks”, “Music”, “Playlists” and “Podcasts”.  None of these folders contain anything called “root directory”.  I don’t know what to do here, are there instructions in plain English somewhere?