Prawns can be cooked with or without their shell, but most recipes call for the shells to be removed which is easy to learn. Larger prawns are easier to peel so practice with these first. Make sure you wash them before using.
Grip the body of the prawn in one hand and twist off the head with the other
Turn the prawn over and pull the shell open along the length of the belly, working from the head to the tail removing the segments of shell as you go