Hi, unfortunately the wife reversed I to the new sign post outside our house and damages the N/S Rear light cluster, my question is can u just replace the outer lens or do I have to replace the whole unit? And where is the best place to get the part? 

And yes it is the LED part required and I have the estate version, and help would be greatly appreciated.

When I did something similar on my Oct I had to replace the whole unit - search Ebay as they are often available from scrappies - and easy job