Changing GPS Baud Rate with minimal NMEAGPS and GPSPort

Using Arduino Programming Questions
6

Also tried this code;

#include <NMEAGPS.h>
#include <GPSPort.h>

NMEAGPS gps;

void setup()
{
  gpsPort.begin(9600);

  gpsPort.print("$PMTK251,57600*2C");

  gpsPort.end();

  delay(500);
  
  gpsPort.begin(57600);

}

void loop()
{
  
}

but no joy...