Using an External Styles Definition File

Using CKeditor 3.6+
Using Drupal 6 multisite with ckeditor in sites/all/libraries and also in sites/domain.com/libraries

I am attempting to use an external styles definition file and remove all the default styles from the font style list. So far the only way to do that is to remove everything in the default.js file and add my own styles there.
I know that this is not the proper way of accomplishing this because upon upgrade they will be erased.

So... I am following the info from:http://docs.cksource.com/CKEditor_3.x/Developers_Guide/Styles#Using_an_External_Styles_Definition_File
I have added a line to my config.js file here is the code from the file:

CKEDITOR.editorConfig = function( config )
{
   // Define changes to default configuration here. For example:
   // config.language = 'fr';
   // config.uiColor = '#AADC6E';

   config.stylesSet = 'my_styles:/var/www/html/drupal6/sites/domain.com/libraries/plugins/styles/styles/mystyles.js';
};