You can buy the e bike tester or you can just ask the manufacture
You want to change the hall sensors degrees?
Well for 60 deg all sensors marking (label) are facing the magnets.
Well for 120 deg only the middle sensor marking (label) is facing away from the magnets.
To modify your controller to different is more difficult....I don't which in the controller is controlling the motor degrees.
But most controller support both, you can change in the programmable software.