All you need to do is connect with your favourite FTP client and create these folders. Where USERNAME is the username you’d like to load the custom CSS or js for.
Within that user specific folder you can have:
styles: create style.css or admin_style.css
scripts: script.js or admin_script.js
The files are loaded only when they are supposed to. We’re using the file’s last modification time as a version which is a great way to always deliver the latest version to the user.
The plugin is smart and doesn’t run if WordPress is doing an ajax call or performing a cron (maintenance) job.
Additionally the css files are loaded right after the theme has loaded its styles so we can override any previous css styles.