Need Help Adding Addons

Hi all
I'm new to this, i've been trying for half a day to add, and get this plugin (http://www.fluidbyte.net/embed-youtube- ... o-ckeditor) to work. I've read through all the toolbar documentation that comes with CKeditor and followed the instructions that came with the plugin. But I STILL can't get it to work
Are you able to help me get it to work? Thanks