MAC changing

[ias0nas at lycos.com]

Hello,

Is it possible to change the MAC address of a packet after I have
builded it?
I used impacket to build a packet that does not provide the function to
change the MAC. Is it possible to set the bytes of the packet where the
MAC is stored?
I don't want to use system calls to bring the card down and up again
with a different MAC, I need to change it in the packet

Thank you