Step 1

Install GNOME Tweak Tools

$ sudo apt-get install gnome-tweak-tool
$ sudo apt-get install python-apt python-software-properties
$ sudo apt-get install gedit
$ sudo gksu gedit /etc/lsb-release

It will open an empty text file (you can use any text editor instead of gedit)

Add the following in the text file:

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=12.04
DISTRIB_CODENAME=precise
DISTRIB_DESCRIPTION="Ubuntu 12.04 LTS"

Save it and exit.

Step 2

$ sudo apt-get update
$ sudo add-apt-repository ppa:noobslab/themes
$ sudo add-apt-repository ppa:noobslab/icons
$ sudo apt-get update
$ sudo apt-get install mac-os-lion-icons-v2
$ sudo apt-get install mac-os-lion-theme-v2
$ sudo apt-get install zoncolor-themessudo
$ sudo apt-get install cairo-dock cairo-dock-plug-ins

To start cairo docks, Goto  System Tools → Cairo-Docks (no OpenGL)

Go to System Tools → Preferences → Advanced Settings and adjust the theme.