How to install a language pack
Download the language pack(s) you need from http://locales.b2evolution.net .
Unzip the downloaded language pack(s) it into the
/locales folder that you will find in your b2evolution file structure.
If possible unzip your language-packs into the right folder before install.
If you have already installed b2evolution, you need to tell b2evolution that you downloaded a new language pack.
Go to your backoffice > System > Regional and enable the new languages you want to use.
What if my language is not available?
If your locale is not (yet) available for your b2evolution version, you may install a language pack from an earlier version. They are compatible, however you may find many untranslated strings when trying to use it. Once you’ve done that, you may help updating your language.
Also check for partial translations already started on Transifex.