Lemonade-Watermelon Punch
["1 large watermelon (about 25 lb.)", "2 c. water", "1 (12 oz.) can frozen lemonade concentrate, thawed", "1/4 c. grenadine syrup", "1 to 2 (32 oz.) bottles lemon-lime carbonated beverage, chilled"]
["Select a melon about 20 inches long with a flat base.", "The day before serving, cut an 8-inch oval section making a sawtooth edge, out of the top of the melon.", "Remove cut portion and reserve. Using a long handled spoon, scoop out pulp; remove seeds.", "Place 1/4 of the pulp at a time in blender container or food processor bowl.", "Cover, blend or process until pureed.", "(Should have 12 cups.)", "Place melon shell on a large tray.", "Return puree to melon shell; stir in water, lemonade concentrate and grenadine.", "Replace cut out portion of melon.", "Refrigerate overnight.", "Before serving, remove cut portion of melon; pour in lemon-lime beverage to fill 3/4 full.", "Stir with an up-and-down motion.", "Ladle punch into cups."]
["watermelon", "water", "frozen lemonade concentrate", "grenadine syrup", "lemon-lime"]