A small editor script for Unity3D to edit EdgeCollider2D points on editor

EdgeCollider2DEditor.cs

using UnityEditor;
using UnityEngine;
using System;

public class EdgeCollider2DEditor : EditorWindow {

	[MenuItem("Window/EdgeCollider2D Snap")]
	public static void ShowWindow() {
		EditorWindow.GetWindow (typeof(EdgeCollider2DEditor));
	}

	EdgeCollider2D edge;
	Vector2[] vertices = new Vector2[0];

	void OnGUI()
	{
		GUILayout.Label ("EdgeCollider2D point editor", EditorStyles.boldLabel);
		edge = (EdgeCollider2D) EditorGUILayout.ObjectField("EdgeCollider2D to edit", edge, typeof(EdgeCollider2D), true);
		if (vertices.Length != 0) {
			for (int i = 0; i < vertices.Length; ++i) {
				vertices[i] = (Vector2) EditorGUILayout.Vector2Field("Element "+i, vertices[i]);
			}
		}

		if (GUILayout.Button ("Retrieve")) {
			vertices = edge.points;
		}
		
		if (GUILayout.Button ("Set")) {
			edge.points = vertices;
		}
	}

/*
	void OnSelectionChange() {
		if (Selection.gameObjects.Length == 1) {
			EdgeCollider2D aux = Selection.gameObjects[0].GetComponent<EdgeCollider2D>();
			
			if (aux) {
				edge = aux;
				vertices = edge.points;
			}
		}
	}
*/
}

Recommend encapsulating the vertices in a scroll view. eg:
Vector2 scrollPos;
...
scrollPos = EditorGUILayout.BeginScrollView (scrollPos);
...
EditorGUILayout.EndScrollView();