Mainly yes, but if you can find a Independent that has access to the Ford computer system then they can do it as well.
I did it the independant way and I was very happy. Not cheap, 5 litres of the stuff costs around £130 - £150
if you stick to the service schedule it will not need refilling untill around about 84000 mls,
definately a dealer job due to the location of the resevior.
It will show up on the dealer diognostics when due.