You don't need to unzip it on your computer. All you need to do it place it on the root folder of your phones SD card (you need to save it with .zip at the end unless your on Vista/7). Open up Astro File Manager, go to the Home folder (this is your root folder) and click on the .zip file you saved to open the app. Click on it again, then hit "Open App Manager." You should see an install button after this. You need to make sure you have allowed unknown sources to install on your phone. This is done under Settings>Applications>check box labeled "Unknown Sources."