I have an Excel workbook which is protected by a password, so that when you try to open it in MS Excel it requires a password. I needed to transfer this file so it was an Apple Numbers file. Numbers cannot open Excel files that have password protection, so I needed to find a way to unprotect the document open it in Numbers and then save the document as a new Numbers file.
The help in Excel did not give me a solution, but eventually I worked out how it is done, and it is not a case of removing the password protection, here is how to do it.
1) Open the Excel file and enter the password.
2) Click 'Save As' to open the save as dialog.
3) In the bottom left hand corner click on the 'Tools' button.
4) Select 'General Options'
5) This will open a password dialog which will allow you to remove the password and save the file.
This solution makes sense and that once you have added a password on a file the only way of removing it is to save it as another file with the password removed.