To change the pressure indicator on a Prestige clip-on pressure cooker, first, ensure the cooker is completely cool and not under pressure. Then, locate the old pressure indicator on the lid. Gently remove it by pulling it out from its slot. Take the new pressure indicator and align it with the opening, pressing it firmly until it fits snugly in place. Make sure it is securely attached and check that it rises when the cooker is under pressure. This process ensures that your pressure cooker operates safely and effectively.