How to install Google Now on ICS

Google Now is just one of many improvements to the Android experience that Google is introducing in Jelly Bean, but it’s easily one of the most impressive. 
The first means of getting Google Now to work with ICS is a little involved, requiring root, multiple edits to build.prop, and some file renaming. It’s nothing too complicated, but if you don’t want to risk any missteps, you’ll be glad to see that a simpler option is also available. For that, you’ll install a modified Google Now package, already configured to ignore the fact that you’re not running Jelly Bean.

For more information Check out this Link : http://forum.xda-developers.com/showthread.php?t=1749045