Quick answer: the next of kin uses Form MVT 5-6, notarized, with a death certificate. A surviving spouse follows a separate 30-day rule instead.
The general path: a notarized next-of-kin affidavit
No power of attorney alongside it
Because Form MVT 5-6 is itself a sworn affidavit, a power-of-attorney form may not be used in conjunction with it — the next of kin completing the form must sign it personally.
A surviving spouse follows a different rule
Under Ala. Code §40-12-260(7)b.1, a surviving spouse who wants to operate a vehicle devolving from a deceased spouse must present an application for a certificate of title within 30 days of obtaining ownership. The licensing official then transfers the license plate to the surviving spouse directly.
Probated estates go through the executor instead
When the estate has been or will be probated, the court-appointed executor or administrator signs the title assignment, using the same name style shown on the certified copy of the Letters Testamentary or Letters of Administration presented to the licensing official.
A local probate attorney can review your estate — many offer a free consultation.
Each county's license commissioner processes these transfers locally — in Jefferson, Mobile, Madison, or any other county — but Form MVT 5-6 and the surviving-spouse rule under §40-12-260(7)b.1 apply the same way statewide.