How to use TextureImporter to change texture shape

I want to load a 360 image and change the texture shape from the default 2D to 'cube'. I don't really understand how to use TextureImporter to achieve this and I need to be able to to it via script? What I have below does not change the texture shape / dimension.

byte[] bytes = File.ReadAllBytes(imgPath);

Code (CSharp):

1.  
2. Texture2D imgTexture = new Texture2D(0, 0);
3. ImageConversion.LoadImage(imgTexture, bytes);
4. TextureImporter importer = (TextureImporter) TextureImporter.GetAtPath(imgPath);
5.  
6. if (imgTexture.dimension != UnityEngine.Rendering.TextureDimension.Cube)
7. {
8.     importer.textureShape = TextureImporterShape.TextureCube;
9.     importer.SaveAndReimport();
10. }

 

Do it on import in an AssetPostprocessor:
https://docs.unity3d.com/ScriptReference/AssetPostprocessor.OnPreprocessTexture.html

 

That worked thank you!