Astra van rear wiper arm?

Is there a knack to removing the rear wiper arm on an astra van?I have obviously removed the nut but it sems to be stuck solid!I have tried a bar to lever it off but am worried about damaging the screen.
The van is a 2003 spottif model.
Thanks for any advice.
Dave, August 2007


done
spay it pb blaster only alot better
some wipers will need to use a puller

bg, August 2007
lift arm off screen (at right angle to glass) and give it a good waggle .

k, August 2007