The ratings-challenged “CBS Evening News” is set to make a risky pivot following the departure of Norah O’Donnell — scrapping the traditional, anchor-driven format in favor of multi-anchor ensemble

Norah O’Donnell’s exit from “CBS Evening News” Thursday night wasn’t what viewers might have expected. And the successor program that CBS intends to air in its place on Monday will have a similar quality.

Norah O’Donnell bid farewell to her anchor chair at “CBS Evening News” on Thursday night, calling the gig an “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.