Change UI Text in new UI?

How do I change the text in the new UI system from a script? I am making a speedometer.

you get the text component and change its text property.

MyTextObject.GetComponent<UnityEngine.UI.Text>().text = "Insert Text Here";

For UI objects you need to use UnityEngine.UI.

using UnityEngine;
using System.Collections;

using UnityEngine.UI; // <-- this guy right here

public class ChangeTextClass : MonoBehaviour 
{
	public Text textObject;

	void Start()
	{
		textObject.text = "your new string!";
	}
}