The boot of a car securely holds cargo and goods safe from harm. Typically, most trunks are protected by way of a lock that needs a car key to open it. The problem becomes when the key breaks in the lock, making it impossible to both open the boot, and open whatever the key was used for originally. Fixing this problem takes some creative problem solving, but by going through it systematically, you should be able to remove the key.
Spray the penetrating oil spray into the lock hole around the key, soaking it well. Attempt to clamp onto the key with the vice grips. If you can, clamp onto the key and pull it out yourself. If not, proceed to the next step.
Drill a hole into the lock, drilling just to the sides of the broken key, using the drill and drill bits. Drill both sides of the key.
Clamp the vice grips onto the key and pull it out of the lock so that you can get a copy of the key made to access any other parts the key was used for.