How to turn of RenderTopicThumbnail ?

hello, in the SideBar of the current web are displayed the changes made recently. Apart from the topic-titles appear thumbnails - I want to remove these thumbnails from the view because they take up much space and therefore interfere. In Currentweb > WebLinks is a bit of it ("...RenderTopicThumbnail..."), but I do not know how is to comment out correctly this function? ( Explaine it carefully, I´m not expert!) (installed are NatSkin, RenderTopicThumbnail)

-- KlausMann - 03 Feb 2012