How to activate This Class to another

I have a question about using another class in my main GameplayScene. What I am trying to do is make the motions of the X-axis of the phone move the character left and right. Here is what I have in my MotionClass.swift

import SpriteKit
import CoreMotion

class MotionClass: SKScene {

    var player: Player?

    var motionManager = CMMotionManager()
    var destX: CGFloat = 0.0

    override func sceneDidLoad() {

            motionManager.accelerometerUpdateInterval = 0.2
            motionManager.startAccelerometerUpdates(to: OperationQueue.current!) { (data, error) in
                if let myData = data {

                    let currentX = self.player?.position.x

                    if myData.acceleration.x > 0.2 {
                        self.destX = currentX! + CGFloat(myData.acceleration.x * 100)
                        print("Tilted Right")

                    } else {

                    if myData.acceleration.x < -0.2 {
                        self.destX = currentX! + CGFloat(myData.acceleration.x * 100)
                        print("Tilted Left")
                    }
                }
            }
        }
    }

    override func update(_ currentTime: TimeInterval) {

        let action = SKAction.moveTo(x: destX, duration: 1)
        self.player?.run(action)
    }

}

Now I'm trying to call this class in my GameplayScene.swift in the motionBegan function, but I don't know how to go about doing that. I have the variable 'grapple' as MotionClass? but I don't know where to go from there. Could anyone give a good an example on doing this?