How would i add PID control to this servo motor control program. potentiometer

Question

I have installed an AutoPID library (by ryan downing version 1.0.3) to my arduino IDE, but im not sure which parts i will have remove to get the PID to control the servo angle.

Thanks for the reply, but i know i have not used the library in the sketch but i am unsure how to combine it, i have an example code for how to use the AutoPID, i will add it below.

void setup() {
  pinMode(5,OUTPUT);
  pinMode(6,OUTPUT);
  Serial.begin(9600);
}
void loop() {
  float a;
  float b;
  float desired_angle;
  float actual_angle;
  float error;
  float motor;
  float setpoint;

  a=analogRead(A1);
  desired_angle=map(a,0,1023,0,180);

  b=analogRead(A2);
  actual_angle=map(b,125,920,0,180);

   if ( (desired_angle>0) && (desired_angle<70) )
  {
    setpoint=50;
  }
  if ( (desired_angle>70) && (desired_angle<110) )
  {
    setpoint=90;

  }
  if ( (desired_angle>110) && (desired_angle<180) )
  {
    setpoint=130;

  }

  error=(setpoint-actual_angle);
  motor=desired_angle/270*255;


  if (error>0)
  {
    digitalWrite(5,LOW);
    analogWrite(6,motor);
  }
  if (error<0)
  {
    digitalWrite(6,LOW);
    analogWrite(5,-1*motor);
  }

  Serial.print(actual_angle);
  Serial.print(",");
  Serial.println(setpoint);

}

and here is the example code

#include <AutoPID.h>

// PID settings and gains
#define OUTPUT_MIN 0
#define OUTPUT_MAX 255
#define KP 0.12
#define KI 0.8
#define KD 0.003

// Variables
double analogReadValue, setPoint, outputVal;

// Input/output variables passed by reference, so they are updated automatically
AutoPID myPID(&analogReadValue, &setPoint, &outputVal, OUTPUT_MIN, OUTPUT_MAX, KP, KI, KD);

// Setup timeStep
void setup() {
  myPID.setTimeStep(500);
}


void loop() {
  setPoint = analogRead(A3);          // Set our desired point (read the POT)
  analogReadValue = analogRead(A1);   // Read our output voltage
  myPID.run();                        // Run the PID 
  analogWrite(6, outputVal); // Write the PID result to the output
}