Installing the Blackhawk should be straightforward enough. Make sure you select the correct folder.
This is what it looks like after extracting the zipfile following my previous instructions. Open it up to see what you've got.

Note the "Aircraft Container" folder containing the Model, Panel, Sound & Texture subfolders is hidden inside two other folders.
The folder named
UH60Blackhawk is the one you want.
To install the Blackhawk paste the
UH60Blackhawk folder into the FSX\SimObjects\Airplanes directory like this.

Fire up FSX & select Sikorsky under Manufacturer on the Free Flight Aircraft menu.
NOTE: The first variation on the list does not work for some reason so do not select it. I haven't had the time to find out why. All the others work fine.

You will have to validate a couple of gauges the first time you select one of the variations. Then you're ready to go.
Please tell me if that helped.