look here (suggestion: always check the How to folder first):
http://www.subaru-svx.net/photos/files/How-To/10544.jpe
the pin Huck mentions is in the part of the axle housing that attachs it to the transaxle. It can be driven out with a suitable sized punch, bolt, etc.
Beav, a not too frequent member anymore
, popularized the removal of the three bolts at the bottom of the A-arm instead of removing the ball joint, etc. It gives you enough room to wiggle the axle out without disturbing the alignment.