Okla. Stat. tit. 51, § 61

The clerk of such court, at the request of the chairman of the Board of Managers, or of the accused, shall issue subpoena for witnesses, and for the production of books or papers, and in case of disobedience of any such process, the court may order its clerk to issue process for the arrest of such witness or for the seizure of books or papers. All process shall be served or executed by the marshal or his assistant, or by any sheriff or deputy in the several counties of the state.