The is a delicate, high-stakes operation. The official method (Micro SD card clear) is guaranteed but destructive—you lose the program. The third-party tools are seductive but risky, capable of turning a $500 PLC into a paperweight.
: If the CPU has a memory submodule slot, you can plug in a submodule containing an unprotected program. Powering on the PLC with this module will overwrite the existing protected program. s7-200 smart plc password unlock