To use CGDI MB Infrared to write an original key, follow these steps:

1. Insert the new key into the CG-MB device.

2. Click on "Read" to display the related key information.

3. Click on "Reset" to erase the key.

4. Click on "Open/Write" and take note of the prompt.

5. Choose an unused key position data and click to open it.

6. Wait for the write process to be completed successfully.

7. Finally, get into the car to learn the new key.

By following these steps, you can use CGDI MB Infrared to successfully write an original key for your vehicle.