commpubwa on "How do you add a changing header image? (flash?)"

Hi,
Would love to have my header image change pictures (is that called a flash picture? not sure). I'm using the Coraline WordPress theme. Is there a way to do this without opening up the CSS (which I'm not very good at)? Your insight would be appreciated!
Thank you,
Aaron

http://washingtoncommittee.wordpress.com/