Converting PSD to HTML5 & CSS3 with some minor PHP programming

Few years ago we have developed a PHP website with custom CMS for our client. Now he came up with a new design which has to be converted from PSD to HTML5 & CSS3 and implemented into the existing website's functionality taking care of SEO and browsers compatibility. Almost complete existing PHP coding and database structure has to remain but only one module has to be reprogrammed and few things tuned, so PHP skills are required. This is an easy job without hard coding. Approx time of work 3-4 days.