Clear code: using two fingers, hold two buttons at same time (i.e., A & B or B & C, etc.); the LED will rapidly flash 3 times in about 2 seconds; let one of the fingers go (the other finger should stay holding one of the button), and then use the loose finger to quickly click three times on the loose button until the LED light flashes; then release both buttons; then press any one key of the remote control.
When LED light goes off, it means clear code is successful (four keys all empty); if after you press any button of the remote control, the light is still on, it indicates that the original code has not been cleared successfully. You need to re-clear, and only successfully clearing the code can cloning be successful. You can repeatedly clear and clone the code.