Audi A8 2013 Shark Fin GPS Removal

How to remove and test the Shark Fin GPS on an Audi A8 2013 model.
You will need a T20 and T30 bit, to remove the trim.
VCDS is advised to test the GPS both before and after, if you don't have VCDS then access to the Green Engineering Menu is enough to check the satellites being picked up.
The process needs to be done in the dry as once removed the shark fin leaves a hole in the roof!