A fastening system and method to removably attach change part components to a capping or filling machine in order to adapt a general purpose machine for use with a specific size or shape container. The fastening system and method uses magnetic forces to pull component parts into alignment and to interlock portions of interchangeable components. In addition, a blocking component is interposed between two other interchangeable component parts or within mushroom slots, securing the components in place, aided by biasing magnets. This system and method relies on a combination of mechanical and magnetic forces by using mechanical forces to reinforce or supplement biasing magnetic forces, and vice versa, creating a durable connection that will withstand the rigors of the filling and capping process, yet which is simple to assemble and disassemble without tools. The less intricate component parts are less prone to damage during assembly, use, or disassembly.