You stepped out into the brisk morning air, stuck the door key in your car door lock, and turned it like you always do. Unfortunately, the lock was frozen due to some ice collection around the unit, so you tried to jiggle the keys and turn them again, but you heard a loud pop. The key you were holding your hand is now just a head, and the actual key is stuck inside the lock. This is an unfortunate situation, but it is not uncommon. There is always a locksmith who can help you get a broken key out of your car door lock, but there are a few tricks you may want to try first.
Try to retrieve the key with a pair of needle-nose pliers.
Needle-nose pliers are thin at the point, and they do a pretty good job of grasping small or thin things. If you see the edge of the key and it appears to be in a position where you can grasp it, try to use the pliers to get a handle on the piece. Work slowly and carefully if you do manage to get a good grab on the end of the broken key, and make sure you pull the key out of the slot at a straight angle.
Apply penetrating oil to the keyhole and use a thin screwdriver.
If the key fits pretty snuggly in the lock, it can be really hard to get it to budge without a head. However, you may be able to encourage the broken key to move by spraying the keyhole with some good penetrating oil. Give the opening a generous spray down and then use a thin screwdriver to try to reach in and shimmy the key a little further out. If you can get the key worked out enough, use needle-nose pliers to grasp the end.
Use sticky putty to try and pull the key piece out.
The sticky putty that can be used to attach interior decor items to walls is super goopy, sticky stuff, and it will stick fairly well to a lot of things. If you have some of this stuff around, work a ball of it in your hands until it starts feeling sticky and is quite malleable. Push the putty into the key slot with the broken key inside pretty firmly. Allow the putty to sit for a few minutes and then pull it out. If you're lucky, the broken tip will come out as well.
If none of these work, it's time to call an auto locksmith for help. They can help get the key out with specialized tools instead of DIY methods.