Changing oil in a 742 differential.

You could pull it all out with a vacuum jar and a vinyl hose shoved to the bottom of the housing through the fill plug, but any accumulated debris would likely still be on the bottom. If you remove the center section, most folks replace the inner axle seals at the same time. Don’t over-grease the axle bearings, it can push past the outer seals between the retaining flange and the bearing.