Removing the pan is a cinch also. Removing the internal filter and getting the new on is the hard part. All you need to do is remove the 2 bolts that hold that little tube in. Once your in there you'll see exactly what I'm talking about. They say the internal filter doesn't ever need to be replaced, but I replaced mine anyway.
Legacy777 provided this picture of the tube and bolts that need to be removed: http://forums.nasioc.com/forums/show...ghlight=filter
In 1998 Subaru used silicon to seal the pan to the tranny (auto), so I assume they still use this instead of RTV. Nonetheless, good luck.