Below is the html & css code to change the Banners on Attachmax Homepage.
HTML Elements - File located at - templates/frontend/header.tpl
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<div id="branding">
    	<a href="<?php echo $siteUrl ?>"><img alt="<?php echo $siteName ?>" src="images/logo.png" /></a>
    	<a id="buy" href="http://cihilt.com"><img alt="Buy AttachMax Script" src="images/buy.png" /></a>
    </div>

CSS Elements - Files located at css/style.css
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#branding {
	float: left;
	background: url(../images/banner_bg.png) repeat-x;
	border-bottom: 10px solid rgb(255, 218, 103);
}

#branding img {
	float: left;
}

#buy {
	float: right;
}