Okla. Stat. tit. 84, § 103

A revocation by obliteration on the face of the will may be partial or total, and is complete if the material part is so obliterated as to show an intention to revoke; but where, in order to effect a new disposition the testator attempts to revoke a provision of the will by altering or obliterating it on the face thereof, such revocation is not valid unless the new disposition is legally effected.