Secondly, contact your Huququ'llah Representative. If you are in the USA please contact:
Bahá’í Huqúqu’lláh Trust
P.O. Box 697
Wilmette, IL 60091
email: secretariat at ushuquq dot org
As to general guidance on writing Baha'i wills, for U.S. Baha'is the National Spiritual Assembly has provided guidance in the form of a free downloadable booklet, "The Writing of a Will - A Spiritual Obligation." This is only accessible to Baha'is in the USA. To obtain a copy, log in to the US Baha'i administrative website HERE
with your US Baha'i ID number and password
and after you log in, click on this link .
which is visible to US Baha'is who have logged in.
Then scroll down halfway and click on the words:
Information about the Writing of a Will
and you will download the then-current version of this document. As you will see, there are other relevant documents on that page.