Directions are simple. Answer the questions. Review the Document. Print.
Kinyan: Prior to signing the document, the beneficiary(ies) or a representative of the beneficiary(ies), even a self-appointed one, should hand you an item such as a hat or a scarf, and upon taking possession of that item you assume the obligations included in the tzavaah. This is called a kinyan sudar, a halachic action, that transfers property or generates a financial commitment.
Sign the document in the presence of the witnesses (if applicable).
Notarize by witnesses (should be on the same day) (Witnesses should be kosher, i.e. males older than past bar mitzvah who are not related to you, are not your beneficiaries, or related to/beneficiaries of each other)
Store the tzavaah in a place where your beneficiaries will find it when the time comes, e.g. by your lawyer, wife, or daughters.