Heat the grill for at least five minutes on high.
Put the ribs on the grill lengthwise, over to one side. Then turn off the burner underneath the ribs and turn the other(s) down to a low flame and close the lid.
The goal is for the grill to remain at approximately 300°F. Check the temp in about 10 minutes to see where it is and adjust accordingly. If your flame is as low as it will go and the temp is still too high, you can prop the lid open an inch or two with a wad of foil.
At one hour, rotate the ribs 180° so that the opposite long side faces the flame.
While the ribs are cooking, whisk the peach glaze ingredients together in a small bowl.
At 90 minutes (total cooking time) spread on a light coating of the peach glaze.
If the temp remains at around 300° the ribs should cook in about 2 hours.
To check that they're done, hold with tongs from the narrower end. If they bend easily and the meat has pulled away from the cut ends of the bone, they are ready.