Files are compressed to make them smaller, and in turn easier and faster to download.
    Use an application like Stuffit to expand these files. (Click here to go to the Stuffit site.)
    Whatever method you use, you always want to EXTRACT ALL FILES.
    If you're using Windows you can also do the following:
Right-click on the .zip folder.
Choose "Extract All" from the drop down menu. This should expand the update folder.
Double-click on the .zip folder.
From "Folder Tasks" on the left, click Extract all files...
You should get a dialog window that looks likes this:
Just follow the on-screen instructions, which basically means...just keep clicking "Next."