Former foes Larry Birkhead and Howard K. Stern sat side-by-side in a courtroom Tuesday as a commissioner admitted Anna Nicole Smith’s will to probate and ordered that Birkhead, father of the late model’s daughter, would be guardian of the estate while Stern serves as executor of her will. “The will dated July 30th, 2001, is admitted to probate,” said Superior Court Commissioner Mitchell L. Beckloff.