Greetings:
For one or for few documents you do not need a macro.
Superscript removal can be done via pull-down menus and tabs, global search & replace.
Caveat: the resulting document will have all superscripts deleted (neither reformatted as, nor replaced with, normal text characters).
1 Position the cursor at the beginning of the document (via Ctrl_Home keys sequence)
2 From the Editing menu tab click Replace (the Find and Replace window opens)
3 In the Find what: entry box type ^? (explanation ^=escape ; ?=any one character ; ^?^? any two characters ; etc)
4 Leave the blinking cursor in the Find what: entry box, after the ^? string
5 In the Find and Replace window click More >> (a down-menu opens with Search Options and Replace)
6 In the More>> Search Options section search All and unselect / uncheck everything else
7 In the More>> Replace section select Format (a down-menu opens)
8 Select Font… (a Find Font window opens)
9 In the Find Font window, Font tab, Effects, check only Superscript (Preview shows -^?-) ; click OK
10 In the Find and Replace window, leave the Replace with: entry box void of any characters
11 In the Find and Replace window click on Replace All to execute (the deletion / removal of all superscripts)
Save as_ this modified document with a new file name.
End