Well I finally got it done today... Here's a top tip:

DO NOT BOOK IT IN VIA THE SERVICE DEPT. JUST WALK STRAIGHT IN WITH THE LETTER AND ASK IF THEY HAVE SOMEONE ON HAND TO DO IT THERE & THEN.

I did this and avoided losing the car for half a day & some oik going out in it! It took the fella all of two seconds to fit it... What a fuss over something so small