An object reference is required to access non-static member `UnityEngine.Component.transform'

I’m very confused as to why this won’t work, all I’m trying to do is make the box-collider drop down a little when my slide function is called, everything else is working fine but if anybody can explain to me why this doesn’t work it’d be highly appreciated.

using UnityEngine;
using System.Collections;

public class JumpScript : MonoBehaviour {

	Animator anim;
	public AudioClip JumpSound;
	public AudioClip SlidingSound;
	public float jumpSpeed = 1000f;
	float jumpRate = 1.0f;
	bool canJump = true;
	public float slideTime = 1.0f;
	public float timeHeld;




	void Start()
	{

		this.gameObject.AddComponent<AudioSource>();
		this.GetComponent<AudioSource>().clip = JumpSound;
		anim = GetComponent<Animator>();
	}


	void Update() 
	{

		
		if (Input.GetKey(KeyCode.Space)) timeHeld += Time.deltaTime;
		
		if (Input.GetKeyUp(KeyCode.Space) && timeHeld <= slideTime) TryJump();
		if (Input.GetKey(KeyCode.Space) && timeHeld > slideTime) Slide();
		
			timeHeld = 0f;
		
	}


	void TryJump() 
	{
		if (!canJump) return;
		Jump();
		StartCoroutine(JumpCooldown());
	}


	IEnumerator JumpCooldown() 
	{
		canJump = false;
		yield return new WaitForSeconds(jumpRate);
		canJump = true;
		yield break;
	}
	
	void Jump() 
	{
		
		audio.PlayOneShot(JumpSound);
		rigidbody2D.AddForce(new Vector2(0, jumpSpeed));
		anim.Play("Jumping");

	}

	void Slide() 
	{
		BoxCollider2D.transform.Translate(new Vector2(0, -1));
		anim.Play("Sliding");

	}
}

Your problem is exactly what it says. In line 68 you have:

BoxCollider2D.transform.Translate(new Vector2(0, -1));

BoxCollider2D is a class, transform is an instance field not a static field. You can only access it on an instance of a class,
not the class itself.