Do you know wheter can we update Schedule Mode of the detail of task in PEM at once or not?

Summary:

Do you know wheter can we update Schedule Mode of the detail of task in PEM at once or not?

Or if you know the way to remove dependencies between tasks at once, please let me know.

From a certain point in time, we want it is not overwritten by dependencies and we update at once. (Probably we use API)

Would you like give me any information?

Thanks,

Mayuko