Hi all
Thanks for the interesting discussion. I have in past removed the brake caliper assembly with everything else still on the car. This is feasible as once the caliper assembly bolts are removed the caliper can be rotated around the disc to remove it.
The gist I get from the general discussion is that it is better to remove the whole rear suspension assembly rather than trying to split the half shaft from the differential to replace the seal. Probably quicker in the long run/
Steve