Factory antenna removal and Stubby antenna fitment?

[Gti Dave]

Hey guys, I bought the sharan stubby antenna and was trying to take off the factory antenna but no luck. It seems to unscrew but just can't seperate it from the base? Is there a trick to it or is it not meant to be unscrewed? If so, then why doe sit unscrew?

[dazag]

I have a FL Wagon and the antenna unscrews & comes off as expected, so not sure what the difference would be with pre-F/L?