OK, in which case, omit the superscript attribute from the Find expression. Do note that the result if you use Replace All will be the deletion of all parentheses in the document.
Alternatively, you could use a macro like:
Code:
Sub ClrFtNtParens()
Application.ScreenUpdating = False
With ActiveDocument.Range
With .Find
.ClearFormatting
.Replacement.ClearFormatting
.Text = "(^f)"
.Forward = True
.Wrap = wdFindStop
.Format = False
.MatchWildcards = False
End With
Do While .Find.Execute
.Characters.First.Delete
.Characters.Last.Delete
.Collapse wdCollapseEnd
Loop
End With
Application.ScreenUpdating = True
End Sub