The answer to 'how to replace surge protector' is to replace it when it is no longer working effectively or if your home's electrical system experiences a power surge that damages the surge protector. Surge protectors have a limited lifespan and should be replaced every 3-5 years or if they show signs of wear, like the indicator light turning off.
When replacing a surge protector, first turn off the power to the outlet and unplug the old surge protector. Compare the new surge protector to ensure it has the same number and type of outlets. Plug in the new surge protector, turn the power back on, and test it to ensure it is working properly.