How do you change the cartridge

How do you change the cartridge on the motor cause I am build a scoop like a spatula?
and
how would I change my code to do it if it has two motors and I need to make it move so both motor move the same time and the motor move very slow but still making it have the same hold load on it.

Code:

#include “vex.h”

using namespace vex;

int main() {
// Initializing Robot Configuration. DO NOT REMOVE!
vexcodeInit();

// Define motors
motor motor3 = motor(PORT3, ratio18_1, true);
motor motor8 = motor(PORT8, ratio18_1, false);

// Define drivetrain
drivetrain drive = drivetrain(PORT1, PORT2, 319.19, 295, 170, mm, 1);

// Define controller
controller Controller1 = controller();

// Set the motor velocity (adjust as needed)
int maxSpeed = 50; // Maximum speed for the drivetrain
int slowSpeed = 10; // Speed for motors 3 and 8

while (true) {
// Get joystick values
int verticalLeft = Controller1.Axis3.position(); // Get vertical position of the left joystick
int verticalRight = Controller1.Axis2.position(); // Get vertical position of the right joystick

// Calculate the adjusted speed based on joystick position for the drivetrain
int adjustedSpeed = (maxSpeed * verticalLeft) / 127;

// Drive the drivetrain with adjusted speed
drive.driveFor(adjustedSpeed, percent);

// Control motors 3 and 8 with the right joystick for up and down movement
if (verticalRight > 10) {
  motor3.spin(forward, slowSpeed, velocityUnits::pct);
  motor8.spin(forward, slowSpeed, velocityUnits::pct);
} else if (verticalRight < -10) {
  motor3.spin(reverse, slowSpeed, velocityUnits::pct);
  motor8.spin(reverse, slowSpeed, velocityUnits::pct);
} else {
  motor3.stop();
  motor8.stop();
}

wait(20, msec); // Allow other tasks to run

}
}

make the motors a motor link so they move together and top change a gear cartrige you unscrew the motor case put in the desired cartridge and the screw the motor case back on.

use this code when grouped

motorgroup3.spin(FORWARD, slowspeed, velocityUnits::pct)
motorgroup3.stop()