Okla. Stat. tit. 58 § 8
When it is made to appear that any probate matter pending in any court of this state which, by acts of Congress and the Constitution, was transferred from the courts of the Territory of Oklahoma and the United States courts in the Indian Territory to the courts of this state, is not in the county where the venue of such suit, matter or proceeding would lie if arising after the admission of this state into the Union, the court where such suit, matter or proceeding is pending shall, upon the application of the guardian, executor or administrator, or any other person having a substantial interest therein, or upon its own motion, when a proper showing has been made for a removal, within twenty (20) days after application is made therefor, make an order transferring such suit, matter or proceeding to the county where the venue would properly lie if such suit, matter or proceeding had arisen since the admission of this state into the Union, by transmitting to such county the original papers, together with certified copies of all orders and judgments, upon the payment of all accrued costs: Provided, that where any minor is the owner of an estate situate in a county or in counties other than that of his domicile and a guardian or curator has heretofore been appointed for such minor or his estate in any such county other than that of the domicile of such minor, such suit, matter or proceedings shall be transferred in the manner and upon the conditions herein provided, to the county of the domicile of such minor; And provided, further, that such original papers, together with such certified copies of all orders and judgments, shall be filed in the court to which such matter is removed, and the same shall proceed as if ordinarily filed therein, without further service of notice.
Okla. Stat. tit. 58, § 8