Requires opening the router's casing to short-circuit specific pins (boot shot) to force it into "Download Mode." This allows a PC to recognize it via a USB-to-USB male cable for firmware flashing. Requirement: Often requires a USB male-to-male cable and third-party tools like Huawei Flasher DC-Unlocker Critical Firmware Versions Version Status Firmware Example Unlocking Complexity New/Secure 21.311.01.01.366+ High (Likely requires Boot Shot) Specific Regional 21.327.01.01.1477 Moderate (May have free software solutions) Old/Standard 21.316.01.00.406 Lower (Often flashable via LAN/USB) Key Considerations & Risks Warranty Void: