Modify existing Wordpress plugin for related posts

Hi, your job is to modify this plugin: [login to view URL] Basically make it compatible with latest WP and then instead of using the Wordpress thumbnail it should fetch the first image in a post (the URL! e.g. [login to view URL]) and then it should append _thumb to the image Basically it should then look like this: - I still need to be able to use that as a Wordpress function to display the related posts in the sidebar or the footer. Budget is $50 Thanks, Oliver