Removing colliders from terrain trees

How do you remove a tree collider from a terrain tree ? I am using an old code that detects the closest terrain tree and deletes the mesh of it if u click on it. At the end there are 2 lines to remove a collider from that tree, but that doesn't seem to work on newer versions of Unity. What is the solution to this ? I've been looking for a long time and haven't found anyone solving this problem. Maybe it's time to leave terrain trees and have trees as game objects ?

The 2 lines that removed the collider of the terrain tree on older versions:

             float[,] heights = terrain.GetHeights(0, 0, 0, 0);
             terrain.SetHeights(0, 0, heights);