Add functionality to online newspaper website

I have a newspaper website. It uses PHP with Yii framework, MySQL db, plus front-end. It's a large scale website, so it has a lot of code, much of it is not pretty. It has around 40 tables in the database. There are articles of different categories which are posted from an admin page. I need to add another category of articles, which can be posted from the admin page. It should be similar to other articles, but at the end it has to have a form for users to upload pictures. There are other units that already use uploaders, so you can reuse those, and in general most of the code can be reused, but it's quite messy.