My b2evolution Version: 2.4.x

Hi all
I'm using evocamp for religeous blogs. It looks good.

http://2viets.com/b2evo/phuochue/phatphap.php

I want to resize to make right column narrower (widening left column) or remove right column completely.

Following is part of .css file i'm guessing that need to be modified but dont know which is which.

#contentleft {
width: 680px;
float:left;
padding: 0;
margin: 0;
}

#content {
width: 499px;
float: left;
margin: 0 1px 0 0;
padding: 0;
}

#midcontent {
font-family:tahoma,geneva,verdana,sans-serif;
font-size: 8pt;
width: 160px;
float: right;
margin: 0 0 15px 0;
padding: 15px 10px 15px 0;
}

#contentright {
font-family:tahoma,geneva,verdana,sans-serif;
font-size: 8pt;
width: 250px;
float:left;
padding: 15px 0 15px 15px;
margin: 0 0 15px;
}

#sidebar {
width: 250px;
font-size: 8pt;
float: left;
margin: 0;
padding: 0;
}

Please help. Thanks in advance.

T