Prepare your eating area if you're eating crab at home. Lay newspaper or butcher paper on the table to collect juices. Decide if you're going to eat the crab as you crack it or collect all of the meat on a plate before you eat it.
Rip off the claws and back and set them aside. Pull out the inedible fibrous lung areas, called "the devil,‚" located around the edge and discard.
Pull out the intestines and discard. There might be a yellowish cream called "mustard‚" inside. Some people like to eat this. Discard bones, cartilage and gills.
Break the crab in half at the midsection where you pulled out the intestines. Rip the two halves of the body in half and squeeze, cut or pick out the meat. Make sure to check all the nooks and chambers.
Use a crab cracker to crack the claws at the joints. You can also press blade side down with a knife if you don't have a crab cracker. Since the claws have cartilage inside, you may find it easier to suck the meat out, rather than pick it.
Crack the legs with the crab cracker and pull the meat out with the spatula. The legs have very little meat.
Squeeze lemon over the crab meat or dip it in mayonnaise or other seafood seasoning.