ignition cylinder locked. on 2002 Pontiac Aztek

My key can't enter the ignition cylinder. It's seen like the wrong key but it's not. what should I do to unlock this problem?

Asked by for the 2002 Pontiac Aztek
You mean the key wont even go into the switch, at all?? Does it work on door locks?
Thanks for your concern. Yes, the key does work on door locks. It just doesn't enter the switch at all. The steering wheel is also locked as it usually does, but always opens when I twist and turn while the key is in. Is this a mechanical or electrical problem? what should I do?
Have the lock cylinder replaced.
im trying to figure out how to remove the cylinder if the key wont insert all the way so you cant turn it.