Final answer:
To insert the catheter further, you should insert until resistance is met. Follow the given instructions and do not withdraw or remove the catheter.
Step-by-step explanation:
To insert the catheter another 2.5-5.5 cm (1-2 inches), you should insert further until resistance is met. This means that you continue advancing the catheter until you feel a slight resistance, which indicates that you have reached the desired location. It is important to follow the given instructions and not withdraw the catheter or remove it completely.