Turn off power to the pool light at the breaker
Verify the power is off
Remove the light fixture from the pool wall
Bring the fixture above water
Open the light housing
Remove the old bulb
Install the new bulb of the correct type and wattage
Replace the gasket if needed
Reassemble the light housing
Test the light before reinstalling
Place the fixture back into the pool niche
Secure the fixture in place
Restore power and confirm the light works