hey i dont know what system you want to spoof on but if you is linux that should be simple but when i comes to windows you gotta be a genius, for windows there are tons of way but they are all as hard as hell. but u can do precision hacking eg edit all out going packets to send out false ip adddress, mac address and headers. then you should start thinking about reply's. if you are a programming u can write that to be automated and that what i did and i use a dhcp to recieve my replys. hard but saves you.