[egtrix]

Just find the following code and remove it or replace it with whatever ads code you want.

<center><script type="text/javascript"><!--
google_ad_client = "pub-4742914093303881";
google_ad_width = 468;
google_ad_height = 60;
google_ad_format = "468x60_as";
google_ad_type = "text_image";
google_ad_channel = "";
google_color_border = "3F559C";
google_color_bg = "34385D";
google_color_link = "FF9900";
google_color_text = "FFFFFF";
google_color_url = "FFFFFF";
//--></script>
<script type="text/javascript"
  src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script></center>

As for removing the ads area image, this isn't possible as it was designed to have ads in both header abd footer.