How to install new plugins

Hi, I'm trying to install new plugins and I still don't get it to work correctly.

1) downloaded plugin
2) installed on sites/all/modules/ckeditor/plugins
3) added config to sites/all/modules/ckeditor/ckeditor.config.js

i.e. config.extraPlugins = 'SimpleLink';

4) enabled the plugin here: admin/config/content/ckeditor/edit/Full
5) cleared cache
6) I don't see the icon for the new plugin and it does not appears for the editor.

Please help, what step(s) are missing from my list? thanks.

drupal 7
ckeditor module 1.16
ckeditor library 4.4.7