Updating outdated scripts (Creating a hole in Unity Terrain)

Hey, I need help converting these old scripts (All the way from 2012 and from this blog) to work with a newer version of unity. These scripts are used to make holes in the Unity terrain but don't work that great with a semi-new version of unity (2017.3).

Script used for disabling collider on terrain etc. :

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class TerrainHole : MonoBehaviour {
5.  
6. public Collider player;
7. public TerrainCollider tCollider;
8.  
9. void OnTriggerEnter (Collider c) {
10.   if (c.tag == "Player") {
11.      Physics.IgnoreCollision(player, tCollider, true);
12.   }
13. }
14.  
15. void OnTriggerExit (Collider c) {
16.   if (c.tag == "Player") {
17.      Physics.IgnoreCollision(player, tCollider, false);
18.   }
19. }
20.  
21. }

Here is the code for the shader used for making an object transparent so that you can see through the terrain (for more details click here):

Code (CSharp):

1. Shader "Depth Mask" {
2.   SubShader {
3.     Tags {"Queue" = "Geometry+10" }
4.     Lighting Off
5.     ZTest LEqual
6.     ZWrite On
7.     ColorMask 0
8.     Pass {}
9.   }
10. }