Connect the phone to the PC via USB while holding the "Boot Key" (usually the center OK button or the Call button for keypad phones). Wait for Finish:
frequently post tutorials and links for SPD-specific unlocking software. Technician Blogs: Sites like Halab Tech RepairMyMobile nokia spd unlocker tool v10exe free
Instead of downloading unverified .exe files, consider these more reputable options: Connect the phone to the PC via USB