A step-by-step guide to test and replace a faulty electrical outlet:

You can use a GFCI outlet tester. Plug it in to the outlet and follow the prompts. You can also use a no contact tester (safest) to see if the outlet is getting power prior to turning off the power. You can then use either of the testers when the breaker is off to ensure there is no power coming to the outlet.

Next:

If there's power, the tester will light up or beep. Recheck the breaker box for the correct breaker, turn it off and test for current again.

The power is off, no lights or beeping from the tester:

Remove the outlet: Unscrew the screws holding the outlet in place and carefully pull it out of the electrical box. Pay attention to how the wires are connected (take a picture).

Disconnect wires: Loosen the screws holding the wires in place.

Replace the outlet: Install the new outlet by connecting the wires to the corresponding terminals (hot to brass screws, neutral to silver screws, ground to green screw). Tighten the screws securely.

Mount the outlet: Carefully tuck the wires back into the electrical box and screw the outlet in place. Make sure it's level and snug.

Test the new outlet: Turn the power back on at the breaker or fuse box. Test the outlet with the voltage tester to ensure it's working properly.

Always exercise caution when working with electricity and consider hiring a licensed electrician if you're unsure or uncomfortable with any step of the process.