Okla. Stat. tit. 58, § 58-135: Revocation in favor of person entitled

When letters of administration have been granted to any person

other than the surviving husband or wife, child, father, mother,

brother, or sister of the intestate, any one of them may obtain the

revocation of the letters and be entitled to the administration, by

presenting to the county court a petition praying the revocation,

and that letters of administration be issued to him.