Remove password protection from an Excel spreadsheet. Use the password to open the spreadsheet. Click the Microsoft Office Button, point to Prepare, and then click Encrypt Document. In the Encrypt Document dialog box, in the Password box, delete the encrypted password, and then click OK.et a password in an Excel spreadsheet. To encrypt your workbook and set a password to open it: Click the Microsoft Office Button, point to Prepare, and then click Encrypt Document. In the Password box, type a password, and then click OK.