copy my old yii site or modify codeigniter script to use my database

Please read carefully. This is a photo sharing social site: You have to use my existing mysql db because the ios app is already using it. Yii 2 is preferred. Old site is custom framework built on top of Yii 1, so it cannot be updated. No reposting or repinning BUT you must be familiar with Pinterest site categories and user created categories aka 'boards.' Otherwise you will not understand this project. Before proceeding, please visit the links to my old Yii site in attached file. I assume you visited the url's in attached file. As you can see, this project requires the basic features of any social photo site: like, unlike, follow, unfollow, followers, following, comments, delete / report comment, edit profile / avatar, reorder/rearrange boards and select/update board cover. edit post description, report post, admin/users can delete their own post, comments, newsfeed etc.. You can also assume that the Admin panel can manage users, post, comments, boards, main categories, etc.. language support, email notifications, nginx rewrite in backend. OR you can modify this CI script [login to view URL] it has the same features, pages function like my website. except MISSING: grid layout, main categories, user boards, select board cover, slideshow and of course template. Allow admin to HIDE user registration and user upload, change image path to s3. NOTE: no registration or photo upload because it's done via IOS app. But allow user to change avatar (uploads to S3). When placing a bid, please note if want to start from scratch or modify codeigniter script. Thanks