Theme Modify

Hi everyone!, well i’m trying to make a wordpress theme using an existing theme http://fanfusion.org/?preview_theme=wp6 downloaded from fanfusion, I could change almost everything, but i couldn’t change “POSTS” check it http://lainus.eshost.com.ar/wordpress-3.0-es_ES/ I want to put a HEAD http://i32.tinypic.com/2rmwnpw.jpg, a BODY http://img210.imageshack.us/img210/9783/mediooooooooooo.jpg and a CLOSER http://i30.tinypic.com/21cdm36.jpg to a post, like fansites, as you see I could change the header and the Sidebar, but I can`t make anything in the POST, if yo need any code, If you need all my modified theme, I put it! I need a solution please…

P.S.: Is the first time where I modify a WordPress theme