Select File, Save, and click Options. In the Save Options dialog box enter your password in the Password to Open text box. Confirm the password, read and heed the cautionary note, then click OK.When opening the file a Password dialog box pops up. Enter your password to open the file.n the Save Options dialog box enter your password in the Password to Open text box. Confirm the password, read and heed the cautionary note, then click OK. When opening the file a Password dialog box pops up.