CKEditor help

Hello everyone,
I need some help on changing built-in CKEditor from CuteNews.

I'm trying to change the language by adding the lang file (pt-br.js) to cutenews/core/ckeditor/lang folder and then changing the language code to "pt-br" on System Configurations-> Ckeditor. After doing that, the editor disappears. How do I fix that ?

Also, I want to change the skin and add some plugins to it, but I couldn't find the called file index_cke.tpl that have been mentioned in other posts.

And one last question, is it possible to upgrade CKEditor's version? I tried doing it by just renaming ckeditor folder and adding my own build, but it also didn't work.

Thank you

Best regards