Theminig Advanced Forums to look like vBulletin

Would anyone skilled in the area of CSS mind getting me started? I have tried to discover the element (div?) and CSS property that controls the physical position of the Advanced Forum thread table components but simply cant locate anything that makes it move. I think I need to use Clear in the correct place, but not sure where or how.

Currently the user info column (avatar, points, join date etc) is on the left of each forum post and comment. For my forum this uses up valuable horizontal pixel realestate.

I would like to theme the forum so that user info appears as a horizontal row at the top of each forum post.

For example, I want it to look a little like vBulletin layout:
http://www.vbulletin.com/forum/showthread.php?t=275089

Currently it looks like this:
http://socnet.shellmultimedia.com/node/897

The element I want to move (and its contents) is called .forum-comment-left.

Currently it sits to the left of .forum-comment-right. I want it to sit above it. I tried a clear-left and clear-right as a random guess, but no luck.

.forum-comment {
margin: 0px 0px 5px 0;
padding: 0 0 0 0;
border: thin solid black;
}

/* Header at the top of each post */
.post-info {
height: 2em;
}

.postedon{
padding: 0 5px;
float: left;
}

.posttitle{
padding: 5px;
width: 96%;
border-bottom: thin solid black;
}

.forum-comment .new {
float:left;
}

.post-num{
float: right;
margin-right: 5px;
}

.forum-post-wrapper {
clear:both;
border-top: thin solid black;
border-bottom: thin solid black;
}

.forum-comment-left {
float: left;
width: 150px;
line-height: 110%;
}

.forum-comment-left .author-name {
margin-bottom: 5px;
}

.forum-comment-left .picture {
float: none;
padding-left: 0px;
margin: .5em 0px .5em 0px;
}

.forum-comment-left .picture img {
padding: .5em;
height: 85px; /* reducing and unifying size of user pictures Thomas */
width: auto;
}

.author-title, .author-posts, .author-regdate, .author-points {
padding-bottom: .2em;
}

.forum-comment-right {
margin-left: 150px; /*Set left margin to LeftColumnWidth*/
}

.forum-comment-right .content {
margin: .5em;
}

#main #content .node .forum-comment .forum-comment-right .content {
padding-right: 5px;
}

.innertube{
margin: 10px 7px 10px 13px;
}

.forum-comment .links {
text-align: right;
height: 2.5em;
line-height: 2.5em;
margin: 2px 2px 2px 0px;
}