Mk1 golf Wing Mirror Adjuster Removal

Does anyone know how to remove the wing mirror adjuster off a mk1 golf cab, cant seem to find what is holding it on and im trying to change the wing mirrors, thanks

going from memory theres a flat hexaganal bit of metal that screws on, you gotta take the plastic bit and the rubber gaitor off to get to it, then it should just pull through from the outside

Scott