How to change the Xwiki to other language, such as Chinese.

Hello all, I want to change the Xwiki to other language, such as Chinese. I read document this adress http://www.xwiki.org/xwiki/bin/view/FAQ/HowDoIChangeTheDefaultLanguage. But I still don't know how to change to Chinese. Do xwiki has something like language-pack which can put somewhere. Then user can change language conveniently. Or if I have to translate it by myself, can you give me some instructions? Thanks, Wang Ning