I know it's an oldish thread,but I am sure that Ghia moulds are clip on.There should be a nutted clip at the front and rear of the mould.remove the nuts,and gently prise the mould up wards,away from the panel.the plastic clips will most likely break,as they become brittle over the years.
Once the moulds are removed,get a small phillips screwdriver and gently drive the small pin that is in the centre of the clip through.this will allow you to remove the clip.
You will now have a heap of 6mm holes to either fill or hide.