Extension modification or how to modify image in product

I want to design ecommerce website for shirt in which i want to modify image for example product image is shirt now on click i want to only change cuffs and collar like given on this page http://www.itailor.com/designshirts/
i have found this extension http://www.opencart.com/index.php?route ... arch=color product image color swapping. Can we modify this?