Removing 16000 zip extentions from directory?

Hi
i've downloaded a shareware game and when i extracted the rar file , i've find a weird problem : all files have a zip extension, i scanned the file and i've not found any virus so i want to remove the zip extension from all 16000 files so please help me to do this!!

thanks in advance for your help

Select all files and...

img254.imageshack.us/img254/2606 ... 650ei7.png

ImageShack is down for me at the moment, so he's a locally hosted screenshot of what I think AlbatorIV's would be, in case it's down for you as well: