download(http://ckeditor.com/download) the ckeditor code to sites/all/libraries/ckeditor
download Widget(http://ckeditor.com/addon/widget) to sites/all/libraries/ckeditor/plugin/widget
download Line Utilities(http://ckeditor.com/addon/lineutils) to sites/all/libraries/ckeditor/plugin/lineutils

Enable ckeditor_codesnippet module
On profile configure page for wysiwyg module, check "Code Snippet"