On newer vehicles that have the digital odometers they cannot be changed or rolled back to a lower mileage so that would be impossible to do.
Now if the odometer is an older odometer that runs by cable then you can roll those odometers back by hooking the cable to a drill and reversing it.
There was a car dealership owner years ago that got caught reversing the odometers on higher mileage cars and selling them as low mileage cars.
He got a prison sentence for doing so.
Now even with the digital odometers it can still be possible to show lower miles on the vehicle by removing the current digital odometer and replacing the digital odometer that is showing higher mileage with another one from a lower mileage vehicle.
But most legit dealerships would not do that because it can get them in serious trouble for little gain.