My b2evolution Version: Not Entered

I'm trilled to have found this program it is really a time saver! I love the 133t_gray skin and want to set it as a default, it matches my web site perfectly. I would like to be able to change the titles of the categories boxes. wtf? is not a real appropriate title for my young audience. I'm looking in the skins files but not sure where to locate that part of the code.