How do I change an ignition switch in a 2009 Chev Aveo?

Now if you mean the barrell then what you do is insert key and turn to acc position and then look around the lock and you will see a hole and into this hole you push a small nail to push the pin down and then pull teh key gently and the barrell will come out.make sure the steering lock mechanism doesnt drop or you are in the proverbial.if you have lost the key then its down to cutting the whole lock off as you cannot get a drill to drill the spring loaded pin out .make sure you remove the transponder ring before you do anything though and if you replace the barrell or the complete lock you will need a autolocksmith to reprogramme the keys for you ,or remove the chipfrom the old key and put it in the new one and the spare as well or vehicle will not start ,and make sure you remove the transponder ring i know i have already written that but i cannot over emphasize this enough ,if you have lost the keys and no spare then its easier to wait for a new key from dealer