Ouch !
Sounds like a good chance that you spoil the thread and end up changing the
whole mechanism !
I used a hot-air gun, some wd-40 or if it was CRC-556, penetrating oil, a
welding plier and a screwdriver !
I took the nut away, heated the stud a bit and then soaked it with oil.
After a while when the thing had cooled off I soaked it again and gently
twisted the wiper arm - down by the stud - with the pliers and used the
screwdriver to lever a bit  underneath.
I also used an old t-shirt to protect the paint !
Worked for me :)

IF you�re going to whack the  stud, keep the loosened nut threaded on the
top for protection !

Calle

> Something that can work is to remove the 10mm nut, then give the
> threaded stud a rap with a hammer.
>
> -Simon
>
>
> On Jul 13, 2004, at 6:23 PM, Bruce Nadig wrote:
>
> > Another alternative, although I have never had to do this on a
> > Vanagon, is
> > using a battery terminal puller or gear puller. I haven't gone out to
> > my van
> > to see if it would work, but I bet it would.
> >
> > Cheers,
> > Bruce
> > motorbruce
> >
> >> From: Markus Mumper <mumper@USA.NET>
> >> Reply-To: Markus Mumper <mumper@USA.NET>
> >> To: vanagon@GERRY.VANAGON.COM
> >> Subject: Re: Wiper Arms
> >> Date: Tue, 13 Jul 2004 17:07:06 -0700
> >>
> >> A good yank - I just removed and replaced mine on my '87, took a
> >> little
> >> leaverage to pry them off.
> >>
> >> Markus
> >>
> >> pete owsianowski <pnocean@EARTHLINK.NET> wrote:
> >>
> >> > Hope this isn't too trivial:
> >> >
> >> > I can't seem to budge the wiper arms on  my '87 Westy.  I would
> >> like to
> >> > remove them to clean up and repaint.  I've removed the small nut at
> >> hub
> >> of
> >> > the wiper arm per Bentley, but it seems solidly in place.  Does the
> >> 2nd
> >> > larger nut have to come off, also?  Don't want to damage anything,
> >> but
> >> do
> >> > they need a good yank?  They are working fine.
> >> >
> >> > Thanks for any info
> >> >
> >> > Pete
> >> > '87 Westy
> >> > 'Joe's Van"
> >> >
> >
>