Hide Admin Bar in 3.4.2 iFrame

I am a non-coder, working to create a help file for site admins in a multisite network. I am using a plugin called WP Client Reference and have found that I can create an instance of my theme options page in an iframe. With that ability, I can add text and explain a feature to the site administrators.

However, it is pretty distracting to see the WordPress menubar floating across the top of the iframe. Is there any way to hide it? I also have Osh Admin Bar activated, so I have no idea which I am seeing. I don’t understand what the admin bar is. All I know is that I don’t want a menu sitting inside the iframe, when there is already one at the top of the page.

I saw where some mods were recommending the use of

#wpadminbar
{ display: none; visibility: hidden; }

But, I have no idea where to put it to use in this situation.

Anyone here who can help me?
Thanks!