[Request Tutorial] How to translate Blender UI from Translation tool?

Hello everyone. As I’d like to translating Blender UI to my country language so I’m still confused. So, how to do it by myself? The tutorial would be great.

If your language is not one of those that come with blender you could look at http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.60#Internationalization (old but may still be relevant)