How to Remove the Featured Image in this Theme?

I launched Firebug, and I have a clue as to what needs to be removed, however I can’t find this code.

I looked in the style.css and header.php, but I can’t find it.

One of my issues with Firebug is figuring out where the code resides that Firebug reveals to me.

This WordPress thread says to remove:

#header-image {
	height: 200px;
}

but in my style.css, I don’t have that.

Which is the featured image on that page?

You ought to be looking for that featured image’s containing <div> element, then displaying display: none within the CSS of that element.

If you don’t want to be messing around with the theme’s files, try using a Custom CSS plugin to manage your CSS.

Install the Custom CSS plugin as suggested by Andrew.

Then add this code:

#header-image {
	display: none;
}