I have looked at the procedure, and the only thing was that it has you tighten until the rolling torque is some value (10NM or so). I have never seen the torque tool they had in the drawing, so I don't know where you'd get one.
I can say that on my 3 high-mileage MB's, the source of diff fluid drops has been the vent on the top of the diff housing. It looked like pinion seals, but they were OK.

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Prost!