Install Special Symbols plugin to CKEditor

1. Unpack archived files directly to ckeditor/plugins.
2. Turn on the plugin in ckeditor/config.js:

   config.extraPlugins = 'jsplus_special_symbols';

3. Add these buttons to the toolbar definition:
   • 
     jsplus_special_symbols
     Insert special symbol
   See sample CKEditor toolbar configuration to find out more about this step.
4. Now you can use your installed plugins. Do not forget to sure that browser cache was cleared.