How to Change #sidebar-featured-img on custom theme

A webdesigner created a custom theme for our site: http://www.studiou.com

I now need to change an image that is on the side bar here: http://www.studiou.com/pricing/initial-consultation/

It is the pink and white image with a house inside it on the right hand sidebar. I am familiar with code but can not seem to find where I can change this at.

Any advice? Please help! Thank you for your help!