If even the pickle fork doesn't work, use one of these:
http://www.international-auto.com/in...?fa=p&pid=2720
On one of my cars, I tried banging on the side of the arm, tried a pickle fork, no luck. Used this thing, and popped the fucker off with no drama. I don't know if you'll have room for it on the Subaru though.
If you don't want to buy, I have one, but probably won't be able to get to it for a week or so...