How do you remove a broken spark plug that the part the wrench conects to broke off and left the threads still in the block and the porceline is still in the threads?

To remove a broken spark plug with the porcelain still intact, first, ensure the engine is cool. Use a pair of needle-nose pliers or a spark plug extraction tool to carefully grasp and twist the remaining porcelain to break it free. Once the porcelain is removed, you can use a left-handed drill bit to drill into the center of the remaining plug, which may help to loosen it, or use an extractor tool designed for broken spark plugs. If these methods fail, consider consulting a professional mechanic to avoid damage to the cylinder head.