How do I edit a language translation pack?

To edit a language pack, you'll need to edit the configuration file.

Here are the steps to follow.

1. Switch to the language you wish to edit.
   
2. Login as the Adminstrator and go to the Setup->System->Preferences->Advanced Setup section.
   
3. Select the Locale checkbox, then click on the Download button.
   
4. Edit the configuration file in a text editor that can display and save files that have been encoded in UTF-8.
   
5. Validate your configuration at http://www.jsonlint.com
   
6. Save the configuration into a file and upload it into the system.

The new changes should be active immediately.