Once you’ve opened the workbook, click the “File” tab.

Next, click “Info” in the left-hand pane.

On the Info screen, click “Protect Workbook” to show a drop-down menu.

Now click the “Encrypt with Password” option near the top of the menu.

The Encrypt Document dialog box will appear. To change the password, type the new password in the text box and then click “OK.” Or, to remove the password, delete the password in the textbox, leave the textbox blank, and then click “OK.”

If you removed the password, then all you need to do now is save your workbook. If you changed the password, you’ll be asked to confirm the new password. In that case, retype the password in the text box and then click “OK” to confirm. Be sure to save your workbook after changing or deleting the password. If you’ve unlocked your workbook but still want certain parts to be difficult to change, don’t forget that you can hide tabs in Excel.