http://youtu.be/A2-ycjzcr4w
Just go to your Crysis 3 installation folder which is in Origin Games in your Program Files by default. Like this: C:\Program Files (x86)\Origin Games\Crysis 3
Open system.cfg file with notepad. You'll see the below commands.
; crysis3
sys_game_folder=c3
sys_user_folder=Crysis3
sys_languages=english,french,spanish,german,turkish,italian,czech,chineset
g_language=english
The "sys_languages" line in yellow is the available languages that are installed on your system. The "g_language" line in red is the current language that the game is using. Simply change the language name in "g_language=" with any of the languages available to you in the list. And save the changes. That's all...
Example:
g_language=english (Game is in English)
g_language=turkish (Game is in Turkish)
g_language=french (Game is in French)