How do you change the terrain?
I would like to change the terrain from the default Yavin to the Coruscant terrain.
I can't find it in the documentations.

You mean the terrain texture? (i.e. sand vs dirt vs stone)

I think, I mean I want the Corusacant terrain with all the buildings as a background.

That's not terrain, that's the sky texture. Just copy and paste the Coruscant one into your default yav sky.

But if you look out while playing coruscant, if you look down, you can see the same building scene. How do I do that?

go to assets/worlds/cor and find cor1_main_1.tga copy that into data_abc/worlds/abc/world1

then go into zeroeditor and go to the texture tab click on an empty (gray_ box) on the right hand side then go to the section on the left hand side where it says texture click browse and find the texture you want in your world1 folder

Thanks so much, that's exactly what I wanted!