# I tested this in kali linux which is debian-based linux
# type <ifconfig> to know your ip address and MAC address
# you will see your MAC address like this -> ether 'MAC address'
#to change the MAC address you have to do these steps
sudo ifconfig <network interface> down
#example -> ifconfig wlan0 down
sudo ifconfig <network interface> hw ether <MAC addr that you wanna change>
#example -> ifconfig wlan0 hw ether 00:11:22:33:44:55
sudo ifconfig <network interface> up
#ifconfig wlan0 up
#NOTE: MAC address will change after the system has rebooted