This addon is a locale. You need to extract it to your /locales folder to install it. For more help with locales check out the help topic here.
Full Simplified Chinese Translation For Vanilla 2. 简体中文翻译, 来自东北大学先锋网技术部.
almost full translation with some pop add-ons' translation.
put the zh_CN sub dir into locales dir, and modify your config/config.php, set locale to 'zh-CN'. Then enable this locale.
* Update 2010-12-23 07:21 GMT+8 updated to 1.1 version. more translations. now 90%+ complete. with popular addons. * Update 2010-12-29 updated to 1.2, more translation. more addon * Update 2010-12-30 fix an error in captured.php, updated to 1.2.1