Bank your coals to one side of the grill. This is the hot or direct side. The turkey legs go onto the cold side or indirect side. You can use a few bricks to make a divider and contain them. I place my wood chunks directly on top of the hot bed of coals.
Lay down a bed of charcoal about 1/2 as high as your grill. Set up a chimney starter. Once those coals are all glowing, dump them on top of your bed in the grill. Add your wood chunks. Place the grill back, unless you have a split grate, then just put the grill on the cold side, place your turkey legs onto the cold side, and put the lid on.
you only need maybe 2-3 chunks of wood for a turkey leg smoke. They should be done in about 3 hours, give or take.