"Remove the hubs and replace the wheel bearings. Drive the old races out with a brass punch. Lightly tap all around the circumference of the race to knock it out slowly. Use the old race to install the new race with a soft mallet. I will tighten the hubs using the Mercedes method of using a dial caliper to check lash."
Others may disagree, but I think it is a bad idea to use the old race against the new. I have always used brass as the contact metal. This avoids any possibility of distorting the race. Then use a 'hard' mallet. Also, tightening new tapered bearings, I prefer to overtighten, loosen, then retighten per the manual. I also will recheck the adjustment several times in the first 100 mi to make certain the races were fully seated.
But, this experience has NOT been with Mercedes. They may have some peculiarity I am unaware of. Simply adjusting the (old) bearings on ours presented no surprises.