Volkswagen will also establish two compensation funds: One to reimburse car owners, one to address excess emissions and "promote green automotive technology."
The automaker says Horn is departing "through mutual agreement."
It's confirmed: Muller, formerly head of Porsche, will take the place of recently departed CEO Martin Winterkorn.
Dealers have been ordered to stop selling EPA-cheating TDI models, but VW is offering a little money to ease the blow on dealers.
Initially, the automaker said the cheat only affected 500,000 U.S. vehicles. Turns out it's way, way bigger than that.