How to Change WordPress to Your Language
How do I get WordPress to use my language?
In this tutorial we’ll detail how you can get WordPress up and running in your own language on an existing installation. To do this, you’ll need FTP/SFTP/SSH access to your server.
Step 1) Head over to WordPress in Your Language and see if your language is listed.
Step 2) Depending on the language, you can click to follow through and directly download WordPress already in that language, such is the case Albanian, Catalan, Chinese, and many, many more.
Step 3) Download WordPress by the usual means of big blue button, and unzip.
Step 4) Copy the contents of wordpress/wp-content/languages to exactly the same directory on your server.
Step 5) Open wp-config.php and scroll until you find where the language is defined, and in the empty quotes add your ISO-639 language code and ISO-3166 country code, as shown on the WordPress in Your Language page, for this demonstration, we’re going to use Taiwanese Chinese.
Step 6) Save your changes and visit the dashboard to confirm the changes are working.
Alternatively, you can use a plugin such as WordPress Language which handles this for you.