how can i get back on to live

I moded my xbox with a chip and new HDD.When I go onto Live it tells me that my box is moded. how do I get back onto live with this box? I have seen that I can get a new eeprom, but from whear? And how would I get it off of a friends box that is not modded?

 

you would have to mod his xbox to get the eeprom and turn your chip off when u go on xbox live.....