Using a other controller

As I have a Arduino UNO and the GRBL CNC shield

In my simple thinking i changed the code as such.

#define DIR_EL 6 /PIN for Elevation Direction/
#define STEP_EL 3 /PIN for Elevation Steps/

#define EN 8 /PIN for Enable or Disable Stepper Motors/

#define DIR_AZ 5 /PIN for Azimuth Direction/
#define STEP_AZ 2 /PIN for Azimuth Steps/

But with no result. So did I mis something