One of our students was having difficulty getting access to his CSS files, so we created this tutorial for him.
This tutorial will show you how you can access and manage your server's files (php, css, etc) directly from your Wordpress admin area using a file manager called elFinder.
Go to http://wordpress.org/extend/plugins/wp-elfinder/ and click "Download Version".
In your WordPress admin area go to Plugins >> Add New >> Upload >> Choose File (select ElFinder from the location when you download it) >> Install Now.
Click on Activate Plugin.
Go to Tools >> elFinder >> Enjoy!