How do you fix door lock when key is stuck?

To fix a door lock with a stuck key, first, ensure the key is not jammed by gently wiggling it while turning. If that doesn't work, apply a lubricant like graphite or silicone spray into the keyhole to ease any internal friction. If the key remains stuck, try pulling it out slightly while turning to relieve pressure, or use pliers carefully for better grip. If all else fails, consider disassembling the lock or consulting a locksmith for assistance.