Convert CSS Menu to WordPress Category Menu

Hello,

I am new in here and welcome to all. I am want to create a new menu for my site. And I want my menu look like Skype menu. I have my CSS code here http://project.khmercms.com/skype/ So I want to change that style my site menu. I want to use with this theme http://project.khmercms.com any body please help me how to do that thanks.