Cleaning a crab quickly is an art. Knowing what not to eat is the trick to eating crab. A blue crab is a good beginner’s crab. Remove the claws and legs first and remove the meat inside. Look on the underside for the apron. Remove the apron from the shell. With a knife, pry open the top shell of the crab. Clean the lungs and face of the crab off of the body. Do not eat the lungs and internal organs. Break open the white meat crab muscle parts left and enjoy.