Dan,
The Google Earth place marker file is in a ZIP file (PCRY.kmz.zip) which most operating systems automatically recognize now-a-days. If you computer won't open it automatically then you may need WinZip, WinRAR or StuffIt to open the file
Save the file to your hard drive. Un-zip it. Then you'll need to have Google Earth installed (http://earth.google.com/). Start up Google Earth and "ADD" the place marker file (PCRY.kmz) to the "Places" window on the left hand side of the screen.
Cheers,
Curtis F.