Those "smooth headed pins" are the back end of 5 bolts, 10 mm Allen socket. They attach the rotor to the hub from the back, so the hub has to come off to get to them.

Good time to repack and inspect the wheel bearings, too, obviously.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!