I have problem with my sky, it is just Black and I did what the documentation said. I copied the KAS sky file and pasted it into my world1 folder and copied all these textures
"kas2_sky" "kas2_sky.tga.option" "kas2_sky_clouds"
"kas2_sky_clouds" <-- TGA "kas2_sky_clouds2" "kas2_sky_dome"
"kas2_sky_dome.msh.option". I only copied these because I only want the clouds in the sky. Could someone please help me?

Did you rename kas2.sky to modID.sky? Did you clean and then munge after you put the new sky files in?

I did name it ***.sky. Clean???

so I munge first than press clean or press clean and than munge?
What does Clean do anyway?

Clean first, then munge.

What does clean do?

I did what you said and my sky is still black and there now is a new sky file that I did not put in there.
My ***.sky file I want is in there.

Okay, just try this:

Go to ..../BF2_Modtools/modID/worlds/modID and do a search on world1 for "sky." Delete all of those files.

Go to ..../BF2_Modtools/assets/worlds/KAS and do a search on world1 for "sky." Copy all of those files into your mod's world1 folder.

Rename kas2.sky to modID.sky.

Clean, then munge.

I will try that.

Do I rename it in capitol letter like this JAB.sky or jab.sky?

I don't think it matters.