Rinse the prawns under cold running water
Remove the head if attached
Pull off the shell, starting from the legs and working toward the tail
Leave the tail on or remove it, as desired
Use a small knife or toothpick to make a shallow cut along the back
Lift out the dark vein with the tip of the knife or rinse it away
Rinse the cleaned prawns again under cold water
Pat them dry with paper towels
Use immediately or refrigerate until needed