@ROb B
As far as the odometer goes you cannot, you can't even do it legally.
Even through you put a new engine in, the truck and parts have mileage.
Just keep your bill with the mileage on it when the new engine was installed.
Ford's data base will be updated with the serial number of the new block in the truck.
Resetting engine clock hours that is displayed in the info cluster,
In the 2019 manual it says use arrow keys to navigate the information menu.
Engine Information - Shows engine hours and engine idle hours.
Hold OK to Reset
Not sure if that resets the PCM memory, there still might be a total hour counter.
If that's what your trying to accomplish.