[Burt4x4]

I would not touch the diff bearings. Your R&P adjustment shims are inbetween the bearing and the differential. Leave them be unless they fall apart when you remove it. They are pressed onto the diff. Make sure NOT to re-install the diff bearing retainers backwards, put them back in EXACTLY they way they were, # 19 in your pic.
A trick to removing that seal inside the diff housing is to use a broom handel from the wheel side and pound it out by simply using the broom handel like a slide hammer, works great and the wood does not mar or damage the diff.
D44 is perrty simple to rebuild once you get familiar with all the parts.
Good Luck
Burt