从K2 Rss提要中删除Joomla元数据

在K2 Rss feed中，如何删除Joomla元数据？我是说 ：

<!-- generator="Joomla! - Open Source Content Management" -->

和

<generator>Joomla! - Open Source Content Management</generator>

这是代码：

<?xml version="1.0" encoding="utf-8"?>
<!-- generator="Joomla! - Open Source Content Management" -->
<?xml-stylesheet href="/media/system/css/modal.css"?>
<?xml-stylesheet href="http://site.com/plugins/system/shortcodes/assets/css/shortcodes.css"?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
        <channel>
                <title>Website</title>
                <description><![CDATA[]]></description>
                <link>http://site.com</link>
                <lastBuildDate>Wed, 28 Aug 2013 10:50:56 </lastBuildDate>
                <generator>Joomla! - Open Source Content Management</generator>
                <atom:link rel="self" type="application/rss+xml" href="http://site.com/?format=feed&amp;type=rss"/>
                <language>en-gb</language>
        </channel>
</rss>

谢谢