Cutting power to CNC Shield V3

I am controlling two stepper motors via the CNC Shield V3 and DRV8825. With no power, the stepper motors turn freely. As soon as I power up the shield and Arduino, the stepper motors lock into place and can only be operated via the Arduino. At the end of my sketch, I would like to cut power to the motors so that they turn freely again. Is there a way to do this?

Use the DRV8825's ENABLE input. Which DRV8825 module do you have?

There is also a setting inside GRBL to do something similar.

Take a look at $4 and $1

IIRC there is also an M command too M17 and 18.