How to change text or content in the system？
Step 1 - Download the original language pack
Step 2 - Search for the text you need to adjust, make the necessary changes
only adjust the text on the right inside the "inverted commas", the text on the left are keys
Step 3 - Save the file and upload to the system
Restore Button - Reverts the language pack to the orignal system settings
How to upload language pack?
Step 1
Public Management > Internationalization > Language Settings > Arabic Language > Select Edit
Note: ensure that the status is enable 
Step 2
Select the green button 
Step 3
Select the respective file (eg. ar_AE file)
Step 4
When you have uploaded the file successfully, you will be re-directed to the language page.
Ensure there is a successful pop-up on the top left hand corner of the page.
This means the new file has been uploaded. 
Step 5
Head over to your exchange site to verify.