There is a good description on how to create a language package for Joomla. (https://docs.joomla.org/J2.5:Making_non-core_language_packs)
Please add the backend translation to the admin folder and all other translations for plugins, modules and the component to the site folder.
On the command line go to the root folder of this repository and run build.bat. This will create installable zip files for each language.
Make sure ZIP is installed (apt-get install zip). Then run build.sh to create the language install script.
Just grab a zip file, for example fr_FR.zip, and install it using the Joomla Extension Manager.