Okla. Stat. tit. 58, § 58-218: Letters of administration revoked on proof of will

If, after granting letters of administration on the ground of

intestacy, a will of the decedent is duly proved and allowed by the

court, the letters of administration must be revoked, and the power

of the administrator ceases, and he must render an account of his

administration within such time as the court shall direct.