Changing a logo image on the static background page

I am looking to change the image on the top left, the “logo” header. This is a custom theme so I think I have to enter it into the style sheet, style.css?

Right now I find:

/*--- Header ---*/
div.header-wrapper{ position: relative; }
div.logo-wrapper{ float: left; }
div.logo-wrapper img{ display: block; }
div.social-wrapper { float: right; text-align: right; font-size: 15px;
	font-weight: bold; margin: 11px 15px 0px 0px; }
div.social-wrapper-text { margin-bottom: 10px; }
div.social-icon:first-child { margin-left: 0px; }
div.social-icon { float: left; margin-left: 11px; opacity: 0.55; filter: alpha(opacity=55); cursor: pointer; }
div.gdl-header-dropcap{
	margin: 0px 10px 20px 0px; float: left; width: 32px; height: 32px; font-size: 0px;
	line-height: 32px; text-align: center; float: left;

	-moz-border-radius: 16px;
	-webkit-border-radius: 16px;
	border-radius: 16px; }
div.gdl-header-dropcap img{ margin: 0px auto; vertical-align: middle; display: inline-block; }

… I dont see any image src or something recognizable having to do with the existing logo. I also cannot find the logos image in the Media Library, but it does have a URL in my wordpress.

Please help!

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