Obtain the death certificate for the deceased. Visit the official website of the New York State Department of Health if you need a certified copy of the certificate. Click "Birth, Death, Marriage & Divorce Records" on the left side of the Web page. Click "Death Certificates" on the right side to view the available options for obtaining the death certificate.
Find the original will if you have not already done so. Check areas of the deceased person's residence where important papers were kept.
Locate the New York State Surrogate's Court with jurisdiction over the county where the deceased person lived. Visit the official website of the New York State Unified Court System (see Resources). Click "Courts" on the right side of the page. Click "Court Locations" in the middle of the page. Select the deceased person's county to view a PDF file of the court locations. Find "Surrogate's Court" on the document. Write the address down or print out the page.
Visit the Surrogate Court's clerks office. Bring the will, death certificate and your state identification with you. Ask the court clerk to search for filed wills if you could not find the document. Ask for a Petition for Probate, instructions, Waivers of Service; Consent to Probate forms -- you need one for each heir -- and the filing fee schedule. Ask for witness affidavits if you are going to file the will.
Write down the deceased person's assets and assign a value to each. Include real estate, bank accounts, automobiles and other assets. Add the figures together. Label the total as the "approximate estate value."
Fill out the probate petition in full. The exact form may vary by county, but you generally need to include the name and address of the executor, deceased person, and all heirs and beneficiaries under the will. The petition also usually asks for the date of death, approximate estate value and citizenship of the decedent.
Fill out the Waivers of Service; Consent to Probate forms. Complete one waiver for each heir. Have each heir sign and date the appropriate waiver. The Wavier of Service; Consent to Probate form allows for the appointment of the executor named in the petition without formal legal service of the probate notice.
Fill out the top section of the witness affidavits. Have each witness sign an affidavit. The affidavit affirms that the witness saw the deceased person sign the will. You may not need the affidavits if the deceased person filed his will in the Surrogate's Court prior to death.
Prepare the filing fee. Check the fee schedule, and note the filling fee for the petition and for each wavier and affidavit, if applicable. Add the total together. Make a check or money order in the amount of the total payable to the court or entity noted on the schedule.
File the Petition for Probate, Waivers of Service; Consent to Probate form, the death certificate, witnesses affidavits and the original will -- if not already filed -- in the Surrogate's Court. Wait for the hearing date on your probate petition to arrive by mail. Carefully read any notices you receive from the court before the hearing, and comply with all court requests and directions.