How do you remove an igniton tumbler with a broken key in it?

To remove an ignition tumbler with a broken key, first disconnect the car battery to avoid electrical issues. Then, use a pair of needle-nose pliers or a small magnet to try to extract the broken key piece from the tumbler. If that doesn’t work, you may need to use a locksmith's tool like a broken key extractor or drill out the tumbler carefully. If you're uncomfortable doing this, it's best to consult a professional locksmith.