Ignition switch assembly iw/cylinder?

The ignition lock cylinder and the engine immobilizer work together, but they are separate components. You can replace the ignition lock cylinder without necessarily replacing the immobilizer system.

The important thing is that the transponder chip inside the ignition key must be recognized by the vehicle's immobilizer system, or the engine will not start.
Replacing the ignition lock cylinder

1. Disconnect the negative battery cable.
2. Remove the upper and lower steering column covers.
3. Locate the ignition lock cylinder and the transponder antenna ring surrounding it.
4. If the old key still turns, turn the ignition to the ACC position and release the lock cylinder using its retaining pin.
5. Remove the old cylinder and install the replacement, making sure it seats and locks correctly.
6. Reinstall the transponder antenna ring and reconnect any electrical connectors.
7. Reassemble the steering column and reconnect the battery.
Important: If your replacement cylinder comes with new keys, those keys may require immobilizer registration before the engine will start. If you still have the original programmed key, a locksmith may be able to match the replacement cylinder to it, avoiding additional key programming.

Here is an image to help as well.