Administering HFNC involves several key steps: 1. Choose the correct size of nasal cannula for the patient to ensure comfort and efficiency. 2. Connect the cannula to the HFNC machine, which includes a flow generator, oxygen source, and a humidification system. 3. Set the desired flow rate, typically ranging from 20 to 60 liters per minute (L/min), and the fraction of inspired oxygen (FiO2). 4. Monitor the patient’s oxygen saturation, respiratory rate, and overall comfort regularly.