how old is it?? if its under one year just call them and they will fix it. no rrod needed.
if you make it red ring and try to have it fixed, that is waranty fraud and we will not disscuss such actions on this forum....
but if for just some strange reason you want to make it red ring, just to see those pritty red lights. well the best way is through heat. however if the chips are in good condition this could be dificult, as the xbox has a heat sensor which will make it shut down to protect itself. wrap it in a towel sealing off the sides and fan area so it cant get cool air and let it run. if you see two red lights it means the heat sensor was tripped and you need to immindeatly turn it off and back on. and let it cook somemore..
remeber if you do this you will be damaging your xbox, AM nor microsoft will be responcible for your actions if you attempt to comit fraud. all I am telling you how to do is see the beautiful three red lights that some of us have become acustom to seeing.