First shed your clothes. Be sure to do this lying on the ground. Be sure to wriggle from your clothes all at once, as if from a singular garment. If you fail at first, dress and try again. This is necessary practise for the next step.

(Julian Nae, the first person to attempt the transformation, achieved this perfectly in only one attempt. A tragic supplier of over-confidence, in his case.)

You must then shed your skin. It is useful to rub yourself against an abrasive surface -- small stones, roots that break through the ground -- in order to loosen your human skin from the body underneath. Be careful, though, not to cut your skin.

Not everyone is capable of this transformation. If you cannot shed your skin after four afternoons spent straining on the ground, you are not made for changing into this body.

(Do not, as Julian did, turn to extreme measures in your frustration. Do not take up a knife and cut yourself from forehead to groin. Do not expect this to achieve anything but your death.)

You will be smaller in your new body than in your previous one, but not as small as the snakes you have seen under patios and bushes. There will be four to six more sheddings of your skin -- depending on your breed -- until you reach your final size. To facilitate this process, you must make a nest somewhere you will not be disturbed. You need not eat.

You will emerge eight months to a year later, a snake. You will mate, eat and grow in small amounts as is natural to these animals.

There is no changing back into a human so be sure, before you start, that this is truly what you want.