1. Download the Languages for WordPress
2. Unzip the downloaded files to a folder on your hard drive.
3. Create a new language folder on your hard drive and add all the .mo file to your language folder.
4. Log into your install using FTP.
Refer to these instructions if you are new to using FTP.
5. Locate the languages folder on your computer.
6. Open up your wp-content folder in your WordPress directory (located within your public_html folder).
7. Select the new languages folder you created on your computer and drag it into your wp-content folder in your WordPress directory.
8. Install the Select Language At Signup plugin.
9. Go to Network Admin -> Plugins and Network Activate the Select Language At Signup plugin.
Once network activated the Select Language at signup option automatically appears on your sign up page.
Changing Language network wide
1. Go to Settings in the Network Admin dashboard.
2. Select the default language.
3. Then click Save Changes.
Changing language on a per site basis
Users can override the default network language settings and set their own preferred default language using Settings > General.
1. Click on Setting > General in the site admin dashboard.
2. Select the default language under site language.
3. Then click Save Changes