Turn off the circuit breaker and verify the power is off with a tester
Remove the existing outlet cover plate and unscrew the outlet
Pull the outlet out of the electrical box
Identify the LINE wires coming from the power source
Identify the LOAD wires going to downstream outlets, if any
Connect the black hot wire to the brass LINE terminal
Connect the white neutral wire to the silver LINE terminal
Connect any downstream hot wire to the brass LOAD terminal, if used
Connect any downstream neutral wire to the silver LOAD terminal, if used
Connect the ground wire to the green ground screw
Tighten all terminal screws securely
Fold the wires neatly back into the box
Mount the GFCI outlet into the box
Install the cover plate
Turn the breaker back on
Press the TEST button
Press the RESET button
Verify the outlet is working properly