Product thumbnails replace main image

I would like the thumbnails under the main image to replace the main image when they are clicked or hovered over, I prefer the hover. It seems like it would be simple but I have yet to find a solution. If you click the thumbs now, it opens their own fancy box, I’d like them to replace the main image and then have their own fancy box. Thanks in advance.

http://ww.wp.xz.cn/extend/plugins/woocommerce/