Bring a large pot of water to a boil. Plunge the lobsters in headfirst and cook until bright red all over, about 10 minutes. Using tongs, transfer the lobsters to a large bowl. When cool enough to handle, twist off the claws and crack them all over. Remove the claw and knuckle meat and cut the claw meat into 1-inch pieces. Twist off the lobster tails. With a large, heavy knife, cut the tails in half lengthwise down the center. Pull out and discard the black intestinal veins. Loosen the tail meat but leave it in the shell. Cover all the lobster meat with plastic wrap and refrigerate.