I'm doing this thread because I had such a hard time finding someone with the right info. Much thanks to Jeff Perrin.
First off locate a spare center differential. Check the boards or some of the Subaru junkyards on line. You should be able to get one for around 200 or less.
Take it apart. Completely. Don't worry about remembering how to put it back togather. This is easily accomplished by removing the snap ring on the top plate and tapping on the internals with a punch, chisel, your head, whatever...
Now seperate the parts into two piles. This is what your paperweight pile should look like.