Snap-On is a tool company that manufactures a wide variety of tools and tool-storage equipment. The Snap-On name is often associated with durability and reliability and, as such, its locking toolboxes are used by many people who have expensive tools and are worried about security. If you lost your keys or if the lock is malfunctioning, you may need to break into the Snap-On toolbox. Proper tools are needed and it should only be done when you are the legal owner of the box.
Pry the top drawer of the toolbox down slightly with a crowbar. The metal will give slightly but not enough to open it since Snap-On boxes are designed to be resistant to this.
Slide a long, thin piece of metal into the opening made by the crowbar. Push it all the way in so its edge touches the back of the toolbox.
Jimmy the metal piece so it shifts under the lock bar in the back of the box. Lift up on the metal to trip the bar, opening the toolbox.