Adding skybox in Unity-5.3 for cardboard VR?

I have imported the google cardboards unitypackage and it is working fine. Now I want to attach a skybox to the CardboardMain gameObject but I am stuck. The unity skybox component or the skybox mesh cardboard script, neither of them are doing the work. Also I couldn’t not find any post regarding so…

If someone could help me out!!!

Per Blue scene screen with cardboard sdk - Questions & Answers - Unity Discussions it seems the answer is:

CardboardMain → Head → Main Camera → Inspector: Camera → Clear Flags : Skybox

There are two ways I have found.

1 - Easiest. Drag your skybox material into your scene and it replaced the default Unity skybox.

2 - Add the skybox to each Main Camera Left, Main Camera Right.
Then edit the CardboardEye.cs Script. remove “Destroy(customSkybox);” at line 279