Changing picture size for product

Hi,

I’m trying to make a product image smaller, but I’m not sure how to do it. I visited Settings > catalogue, and tried to set the dimensions for thumbnails, etc. My product image is still huge. Here it is:

http://www.healthovers.com/product/basic-healthover/

Thanks,
Aarti

http://wordpress.org/extend/plugins/woocommerce/