NOTE: In this example we will change the MAC address for the eth0 interface
Open your Command Line Interface
Now we are going to shutdown the eth0 Interface using the command below
ifconfig eth0 down
Now we change the Hardware Address for the eth0 interface
ifconfig eth0 hw ether 00:1d:72:dd:00:6f
Now we activate the eth0 interface again
ifconfig eth0 up