Problem with agregado’s theme

Hi,

I have one problem with this theme I want to put an image at the first entry of the blog but I don’t now how, plz help me, I want something like this:

https://img136.imageshack.us/img136/3748/justlikethisqi6.jpg

A demo of the original theme:

https://www.darrenhoyt.com/demo/agregado/

Download theme:

https://www.darrenhoyt.com/downloads/agregado.zip

Thanks!!!!