How to Extend banner top header behind TOP MENU and Logo

Hello All!

I use OC 1.5.6.4 and the "METIS" theme from themeglobal.com.

I want to transform the theme at homepage to look like this: http://www.willowtree.com.

How I can extend the banner to the top of the "header" under or behind the "Top Menu", the logo and The "welcome" message?

Thanks you,

@ventienda before @ddm

>> How I can extend the banner to the top of the "header" under or behind the "Top Menu", the logo and The "welcome" message? <<

strictly technically, by stealing the both Stylesheet Files from the other Site, and using parts of the Style Code, found, to make it work, as on the other Site.
Ernie
openshop.li/cart/
PS: it would not even be illegal...