System locale

1. Ensure System has correct locals sudo locale-gen es_ES

   The hosting system must have the correct locale as gettext depends on system libs for localization - see HowTo : Change Locale (Language and Character Set) in Linux

2. Click the gears icon on the top right corner

3. Select Settings tab
4. Click System Settings
5. Select Localization tab
6. Change sLanguage to one of the available languages in the drop down.