Put the crab in the freezer for 15-20 minutes to slow it down.
Fill a large pot of water about 10-15 cm from the top. Add a handful of salt, and bring it to a boil.
Put the crab on its back. Lift the flap on the back end, and put a screwdriver against the hole that is revealed. Put another screwdriver against the head.
Simultaneously, plunge both screwdrivers into the crab. Wiggle them around to kill the crab more quickly.
Boil the crab for 13-15 minutes.
Melt the butter in a bowl in the microwave. Add the lemon juice.
Serve with the melted butter. Goes well with garlic bread.
