To install it:
Admin Control Panel->Appearance->Import a Language->
- Import from uploaded file:Select the file to import.
- Overwrite language:select the language you want overwrite or to import the phrases.
- Press import button
Note: You will find a complete translation for the add-on interface and admin control panel options.
I left the style properties as its easier to use in English because its hard to find words in arabic with the same meaning.