So best laid plans of mice and men... got the car up on stands, pulled out heatshield, driveshaft and transmission mounting (supporting gear box on jack) and then couldn't get the larger roll pin out from the gearbox-to-shifter coupling. Spent a while hammering and swearing to no avail; going to try drilling it out unless someone comes up with a better suggestion.
Gave up with the center diff and attempted to pull the rear diff - which was (of course) also corroded into place. One of the 4 long bolts from the support carriage wouldn't release. The only luck I had here was that the rear long bolts were also pretty bad and the whole stud came out when I tried to remove the nut... at least that way I was able to tilt the differential down whilst attached to the carrier and grid off the top of the stuck bolt (being very care so close to the fuel tank).
Don't you just love working on older cars...?
PS. As you might have guessed this is the Forester, not the LGT.