Norah O’Donnell bade farewell to her anchor chair at “CBS Evening News” on Thursday night, calling the gig the “honor of a lifetime” — as the network prepares for an overhauled broadcast. “It has been an incredible five and a half years,” O’Donnell said. Oprah Winfrey surprised O’Donnell, 51, with a montage that featured interviews with Pope Francis and former Vice President Kamala Harris and on-location coverage across roughly 1,300 broadcasts.