Okla. Stat. tit. 30, § 30-3-105
Court appointment where nominee is unable, unwilling or
cannot qualify to serve.
In the event the person nominated is unable, unwilling, or
cannot qualify to so serve, the court shall make a finding of such
fact and shall proceed to the appointment of a guardian as if such
nomination had not been made, taking into account any alternative
guardian named in the nomination.