Not sure if there is an easier way to do this but this technique has served me well.
Basically, you open your internet browser(doesn't work on Chrome) and type in your router address. It is usually 192.168.2.1.
You'll be brought to a sign in page.
The password is admin (unless someone changed it).
If there is a username box, make it admin as well.
Once logged in, you have to find the Wide Area Network settings. Once you found it, you need to look for your MAC Address (the one you can edit).
All you have to do is change a few numbers/letters in your MAC address and apply. Once you click apply, you will have to reset your modem because you would have gotten disconnected from the internet. Just unplug it for 5 minutes then plug it back in.
Once the modem turns on, you should have a new IP address and be connected to the internet once again.