It's the app with a blue background and white F. It's the icon with three lines in the upper-right area of your screen. It's located near the bottom of the menu. A list of languages will appear. The language currently being used will have a highlighted circle next to it. Facebook's interface will now be displayed in the language you selected.
افتح تطبيق فيسبوك Facebook. انقر على زر القائمة Menu. انقر على خيار إعدادات التطبيق App Settings. انقر على خيار اللغة Language. انقر على لغة.