Upgrading CKEditor

https://docs.ckeditor.com/#!/guide/dev_upgrade

Download new version, copy and replace all files exept

custom files:
1) ckeditor-connector.js
2) config.js
3) contents.css

custom plugins:
1) plugins\smiley

custom skins:
1) skins\teamlab

additional plugins:
1) codemirror
2) fakeobjects
3) filetype
4) oembed
5) teamlabcut
6) teamlabquote