How to change or add themes for Unity? [duplicate]

Possible Duplicate:
How do I change to a theme not listed in the Appearance screen?

Does anyone know how to change themes ?

There only 4 themes , can we add more themes by download it , i try to download some themes that i like but there no option to install it , any idea .. how to add more themes ? cause i try google it need to change into gnome or something like that i just like keep unity with blackbuntu themes

Solution 1:

you can download myunity from the ubuntu software center, you can change with it a lot of options, and you cane change the icons and appearance themes.

or you can use this simple way explained in this post:
http://www.omgubuntu.co.uk/2012/03/how-to-easily-skin-ubuntus-unity-desktop/