Upfront "Spirit" Theme Blog/Category image changes

Okay, I figured out how to delete/change the "Blog" image on this theme's blog page - (needed to create the blog page first) but have no idea how to delete/change the very same image at the top of the category pages. An online search of this site didn't reveal the answer.

Thank you.

screenshot - http://www.screencast.com/t/UrPbWAgSiU