Fix Woo Commerce CSS clash with theme

Hi, I've got a woo commerce site running on a WordPress theme. When clicking on a product the visitor is taken to a product page, but we would prefer if it just popped up a larger image instead. I'm looking for someone with experience of woo commerce who could fix this. I have found this article on http://www.skyverge.com/blog/how-to-use-woocommerces-lightbox/ but couldn't get it to work.