Learn how to crack an egg so that you can preserve the shell in simple steps. First take an egg and a butter knife and you have to make a hole at its top. To make the hole gently tap the top of the egg to make a crack. Now insert the knife in the crack and peel its top out. Pour the egg yolk in a container and rinse the shell several times with hot water. Spray an anti-bacterial spray to kill any germs in it and let it dry for sometime with its hole facing downwards.