Plug the flash drive into your computer.
Open "My Computer"
Click on the "Folders" icon in the menu area.
Open the folder that contains the downloaded iFly .zip file. You should see it on the right side.
On the left side should be a listing. My Computer, Local Disk (C:), etc. look down that list and find the description of your Flash Drive.
Left click on the iFly .zip file, and drag it from the right side to the name of your flash drive on the left side or possibly something like "Removable Disk Drive (E:)"
A box should open and say something like "Copying iFlyUpdatePackage.zip from (the old folder) to (the name of your flash drive)" and the little progress bar.
Once the file is transferred, right click on the listing of the flash drive in the left pane. Look down the list and highlight "Eject", then left click on "Eject".
The listing of the flash drive should disappear.
Remove the flash drive, put it in the iFly, and power the iFly up. The file should install itself automatically.