So one morning last week i can out to my beautiful r56 and found that the aerial mast on the roof had snapped off! was probably some drunk yobbo in south London jealous of my car that done it!..

so i ordered a new small bee sting replacement off ebay to screw in but i can seem to remove the rest of whats left of the old aerial! i thought i would have just screwed out easily like in older car when you need to go through a car wash....
So does anyone know the procedure of removing the mast from the aerial? do i need to remove the black plastic casing to access some sort of screw or bolt underneath?
Also by any chance, does anyone know where to get some center wheel caps for the R113 wheels? seem to have lost one
Thanks in advance!