Hold the phone...
We will assume the previous post is regarding replacement of a suspected outlet that is NOT currently a GFI outlet, if so then so be it.
But just in case otherwise...NEVER replace an installed GFI outlet with a standard one unless the GFI function is inserted via the breaker other other location.
I agree, simple replacement is what is required and is cheap, but as I suggested earlier, one should try to find the suspect one first.
Otherwise, for about $3.50 or so you can buy a contractor pack of outlets at Lowes and start pulling outlets out to look for water damage and simply replace them as you go.
Pick up a pack of faceplate gaskets and a couple spring covers and replace all gaskets and any covers that have weak springs.