Short answer. You file a petition for the allowance of the will. It must show, so far as known to you: the jurisdictional facts; the names, ages and residences of the heirs, legatees and devisees; the probable value and character of the estate; who should receive letters; and, if the will is not yet with the court, who holds it.
What the law says
The names, ages, and residences of the heirs, legatees, and devisees of the testator or decedent
Rule 76, Section 2 — Contents of petition. Read the full provision →
What the law says
But no defect in the petition shall render void the allowance of the will, or the issuance of letters testamentary or of administration with the will annexed.
Rule 76, Section 2 — Contents of petition. Read the full provision →
Why the petition is the necessary first step
A will does not transfer anything by itself; it must first be allowed by the court, and the petition for allowance is how that process starts. Rule 76, Section 2 lists what the petition must show — but always so far as known to the petitioner. You are not expected to know every heir's exact age or the estate's precise value at the outset. What the list does is put before the court, at the very beginning, the people whose rights the will touches and the property it will govern, so that notice can reach the right persons and the proceeding can be set up properly.
The five required contents
First, the jurisdictional facts — the death of the testator and the circumstances that place the settlement before that particular court. Second, the names, ages, and residences of the heirs, legatees, and devisees of the testator or decedent: not just those named in the will, but the heirs who would take without it, since they are entitled to be heard on its allowance. Third, the probable value and character of the property of the estate. Fourth, the name of the person for whom letters are prayed — the proposed executor or administrator. Fifth, if the will has not been delivered to the court, the name of the person having custody of it.
If someone else is holding the will
The fifth item deals with a common real-world problem: the will exists, but a sibling, a lawyer or a bank has it. You do not need physical possession of the will to petition for its probate — you need to tell the court who has it. Naming the custodian lets the court compel the will's production so the proceeding can move. So a relative withholding the document does not, by holding it, prevent probate; the petition simply identifies him, and the court takes it from there.
Imperfections will not undo the result
The section ends with a deliberate safety valve: But no defect in the petition shall render void the allowance of the will, or the issuance of letters testamentary or of administration with the will annexed. A misstated age, an heir listed at an old address, a rough estimate of value — these can be corrected in the proceeding, and they will not retroactively invalidate the will's allowance or the executor's authority. Prepare the petition carefully all the same: the heir list drives who gets notice, and the estate's probable value bears on the bond the appointee will post. But an honest gap in your knowledge is not fatal.