You need to edit templates/header.tpl


Remove following lines

Code:
<link rel="alternate" type="application/rss+xml" title="20 Latest videos" href="{$baseurl}/rss/new/" /> 
<link rel="alternate" type="application/rss+xml" title="20 Most Viewed Videos" href="{$baseurl}/rss/views/" />
<link rel="alternate" type="application/rss+xml" title="20 Most Commented Videos" href="{$baseurl}/rss/comments/" />

and

Code:
<TD>[img]{$baseurl}/templates/images/rss.gif[/img]</TD>