How do I remove formatting from a sidebar?

If you take a look at my site you will notice I am using a customized mandingo theme with 3 columns. The main problem I have with it is the right sidebar is just dedicated to advertising. The google ads are actually 160 pixels wide, but because of the stars that are part of the theme, I have to have the sidebar 210 pixels wide (same as the left) otherwise the ads get cropped off on the right hand side.

Is there anyway of removing the formatting on the right sidebar so the ‘stars’ don’t show up and I can just have my google ads?