Banner in USER 9 position

How can i change the size of user 9 position to put a banner that i like?
for example i can put a banner that is maximum 490*75 and i want to put another one size 728*90 (i saw that on another site)
thank you in advance

You need to make first logo less in width:

layout.css:

.logo {
height: 99px;
width: 410px;
float: left;
}

then in index.php of template find this line:

$headerMenuWidth = $templateWidth - 410;

change 410 to new width value for .logo