Quick Image setting on server, project.

Hey, I have ready graphics called [login to view URL], CSS file and other relevant images. I am using an script engine and i need to change there graphics. Problem is the script i am using does not allow to rename files (the one they have on server). So your task is, you need to set [login to view URL], [login to view URL] and [login to view URL] and then 'edit' the existing Css file (by adding our CSS file content on the existing Css file) The purpose here is only to change header and footer rest, the middle part (body part) would not be affected. I need it in FEW HOURS an it's a simple job for expert. I could pay maximum $50 as all images are ready you just need to upload and change the HTML codes etc so that images could reflect on site. Please PM me for clarifications.