How do I clear a misfire code on my 2001 s600 after replacing the bad right coil pack.

Probably because the misfires are still present. Ask him if he replaced the insulation boots also. If he did then you may have an ignition module problem. Thats the box the the coils connect to Get him to test fuel pressure also.

If you have rectified all the faults and are unable to clear the codes, you could try disconnecting the battery, leave disconnected for a few minutes or so and then reconnect, should the EML (Engine Malfunction Lamp) stay illumniated once starting the engine you must still have a fault. Have it re-checked by a reputable garage. You could have a faulty spark were these checked when your coil pack was replaced?

remove the positive battery cable, touch the cable to the negative terminal, (neg. hooked up) for 30 seconds, resets/drains computer charge, then reconnect, at times the light stays lit, when the fault was corrected, every time the ignition is activated, the computer re-scans itself. if fuel tank is more than 1/4 tank, (sometimes it makes it run lean), if it isn' t fixed let me know