Cubemap as sky

I have setup scene with custom skybox,
I`ve apllied my cube map to EditorSkySphere everything works fine but I have a problem with rotation
How I can rotate cube map inside material, or how I can rotate sky shape(EditorSkySphere)
I am want to re-position my sun

Do you use a Reflection Vector to sample the cubemap?

I cannot use the built-in RotateAboutAxis, but have to implement the rotation matrices: