A Midas Muffler tech pointed out the symptoms of worn ball joints when our
85 camper was on their rack, so I ordered uppers and front shocks from the
Bus Depot, and began asking around for advice regarding installation.
I was first led to believe that replacing the ball joints would require
1)removal of the control arm
2)taking it to a machine shop to press out the old and press in the new joints
However, this was not the case with our Vanagon, although this apparently
was common practice with busses.
The old ball joints dropped right out after I unbolted them, the new ones
bolted right in, and I actually spent more time replacing the shocks.  I did
have to purchase a 24mm combination wrench to fit the big nut on the ball
joints and the wheels had to be turned outward to maximize the work space.  
I plan to have the front end aligned for good measure, but this may not be
necessary.
Jim