By default 68 KB comes with English language files. You can create your own language files by translating the files inside the includes/language/english folder.
For example if you are creating a Spanish site then you would create a new folder includes/language/spanish/ and make a copy of the files the in the english folder.
After you have done the translation open the file includes/application/config/config.php and change this line:
$config['language'] = "english";
to your new folder. For example:
$config['language'] = "spanish";