Reset Person Database in Photos

Is it possible to reset one person's face library? If I could "un-name" all the photos that are in the merged person's photos and rebuild one person after that seems like it would be easier too. Again, too many photos to do one at a time so looking for a broader solution.

Thanks!

Update & questions - on my Mac Mini M1, I selected the People & Pets tab of photos, selected everyone and clicked delete so that it would reset all the face matching data. It cleared all the people and began the process of identifying faces again. What I find, though, is that it is adding people back and identifying their names based on what I had selected before wiping the data out. So it must not erase previous assignments but seems to be applying them to a new scan. That means that the two people that were merged are still as confused and intertwined as before.

1) any way to completely erase face elections so it will truly start over?

2) I believe face data is held at the device level, so whatever fixes I make won't make it to iOS or other devices

3) when I "correct" an incorrect face assignment, does the application learn from that and get better?

Thanks for any input those with experience might have.