The smiley face is character code 74 from the Wingdings font, and
the frowny face is character code 76 from the Wingdings font.
For me, the easiest way to search and replace these characters is
to copy and paste them into the "Find what" and "Replace with"
boxes.

Jeanette wrote:

When Auto Correct substitutes a Smiley Face for semi-colon parentheses, and
you later want to use Find and Replace to edit, how do you do it? And how do
you use Find and Replace to look for symbols you've inserted? Say you typed
all Smiley Faces, semi-colon parentheses, and want to change them all to
Frown Faces... what's the procedure?