Can you change skybox textures after firing up with a prefab?

I've got 2 different skyboxes in mind, but won't know how I feel until I get all my other stuff set up in the level which one works better. I'm torn between NightCity and NightBlack-01. Is there a way I can fire up with a NightCity, build my map, then if I decide NightCity doesn't work well switch the texture on the skybox to NightBlack-01 at the end of it all?

or just replace the whole skybox.

I find it a real pain in the ass to line up the skybox textures.

You can replace the skybox textures, but it's easier to replace the entire skybox using the using the prefabs menu.