Hello, if you have a tester you can make measurements until you find two terminals that mark you resistance that is the bimetal that connects with neutral and line, then pushing the lock as if the door is closed between two terminals you have to measure continuity, if you measure continuity in two terminals without pressing the lock is just a bridge that is used to carry current to another part you use only one. The line connector is going to be the one that gives you continuity by pressing the lock and obviously the other is the return to the board.