Is there a way to enable or install the full version of CKEditor in CiviCRM 4.6.x?
The difference between the "full" and "standard" CKEditor is one of plugins.  You can drop additional plugins into the ckeditor plugins folder at: &lt;civicrmroot&gt;/packages/ckeditor/plugins.  Depending on the plugin, you may also need to edit the config at &lt;civicrmroot&gt;/packages/ckeditor/config.js.  Detailed instructions are available here.

I've had perfectly good success simply dropping in the latest version of CKEditor (https://issues.civicrm.org/jira/browse/CRM-16053).

UPDATE: I found that newer versions of CKEditor strip out the "meta" tags from the templates unless you edit config.js.  Also, be sure to clear all caches (including browser caches) or you may find that your CKEditor toolbar button icons are messed up (because of the wrong offset)