HOWTO : MAC Changer on Ubuntu Desktop 12.04 LTS

Mac Changer is a GNU/Linux utility for viewing/manipulating the MAC address of network interfaces.

Step 1 :

sudo apt-get install macchanger macchanger-gtk

Step 2 :

To run it. You can run it at any directory.

macchanger eth0

or

Graphical interface -

macchanger-gtk