What operating system are you running? Windows / MacIntosh? Which version?
Windows XP handles the zip files if you just double click on them. It will open as a folder, and over to the left, under Folder Tasks, there should be an option to Extract All Files.
For Windows versions prior to XP, go to
http://www.downloads.com, and search for unzip, or something like that. The standard is WINZIP, and it comes with a free trial. I also once used a program called ENZIP, which was freeware.
Can't help if you're MAC. But I bet someone else can.
JanetC