Here are the directions from Zapperplans.com

Zapper Instructions.

Plug a working 9-volt battery into the battery connector.

Clip each alligator clip to an electrode (which can be any piece of copper, stainless or brass wire or even a stainless steel spoon or other handy implement -Dr. Clark recommends copper pipe in her book).

Wrap the electrode in a damp piece of cloth or paper towel, to ensure good contact.

Hold one electrode in each hand for a duration of 7 minutes.

When the 7 minutes are up, take a 20 minute break, then repeat step 4.

Repeat step 5 again for a third and final Zapping.

After this you have been fully zapped for parasites according to the Clark Zapper method.

These instructions are available at
http://www.zapperplans.com/zapinstr.txt