Babel / Installing Language Packs
From Eclipsepedia
< Babel
Galileo
Simply unzip the Babel language pack ZIP file in the dropins/ folder of your Eclipse installation. Launch Eclipse with -nl (locale) if your operating system is not using the same locale as the language pack.
Ganymede
See instructions for Galileo.
Europa
Unzip the Babel language pack into the eclipse/ folder. The Babel ZIP file contains a plugins/ folder with plugins that will be unzipped in the correct location. Launch Eclipse with -nl (locale) if your operating system is not using the same locale as the language pack.