Need to make right sidebar width smaller

Hi, I need to make my right sidebar width smaller. I know I have to do it through style.css but am not sure exactly what to change. I tried changing the width of the secondary sidebar but then my content started overlapping the sidebar. I assume I have to take away some width from one area and add on to another but am not sure which ones. my site is muscle-e[dot]com

Here is what i think the relevant code sections are but am not sure. Could you please let me know thanks.
[ Moderator Note: Please post code or markup snippets between backticks or use the code button. ]

#container {

	width: 1060px;

	margin: 0 auto;

}

#main {

	padding: 15px 0;	

    background: none;

}

#main-fullwidth {

    padding: 15px 0;

    background: none;

}

#content {

    overflow: hidden;

    float: left;

    width: 620px;

    margin-left: 140px;

}

#sidebar-primary {

    overflow: hidden;

	float: left;

    width: 160px;

    margin-left: -800px;

}

#sidebar-secondary {

    overflow: hidden;

	float: right;

    width: 280px;

    margin-left: 15px;

}

Regards

Danny