First, you must have the Aircrack-ng Suite of tools installed so we can use airmon-ng to scan for active hosts:
**IMPORTANT: Your wireless card does not have to be compatible for packet injection!!! If it will work when you type airmon-ng start then you are good to go! 99% of wireless cards will work for this!
sudo apt-get install aircrack-ng
Next, you must install macchanger, its a tool