Place water, kosher salt and brown sugar in an 8-quart plastic container and stir until fully dissolved. Add the ice before submerging the turkey legs in the brine. Cover and refrigerate for 4 hours or up to 12 hours.
Set up your favorite smoker and add a handful of hardwood chunks. If you have heat control, set it to 150 to 170°F and allow the wood to smoke for approximately 30 minutes.
While the smoker is heating, drain the legs, pat them dry, and arrange them on a rack. Smoke the legs on the rack for 3 hours, rotating the legs halfway through.
Heat your oven to 350°F. Make 2 pouches out of double-layered heavy-duty tin foil, adding 3 legs and 1/2 cup of chicken stock to each pouch. Braise the legs in their pouches for 1 hour, then carefully drain and reserve the jus.
Defat the jus, remove the skins and serve the legs alongside the smoky jus.