1993 Grand Prix Key cyclinder replace

The key has snapped off in the key cyclinder, I have gotten the broken key out, and need to replace the key cyclinder, any help on how to get the cyclinder out??

that car has the "square column", which is not user serviceable due to special tools needed to change it out. you'd almost be better off scouring a boneyard for a used column, and replace the whole thing.