The drive unit [A] is attached to the base unit by 4 screws. You must not unscrew or loosen these screws.
As the base unit is made of plastic, applying a strong force may cause the base to distort. At the factory, the drive unit is attached with a special tool to prevent the base being distorted. Attaching the base outside the factory poses a great risk of distorting the base, making it impossible to ensure accurate transfer.