Open word options
Click “popular”
Check mark on “Show Developer tab in the ribbon”
Open your document
Click “Save As” -> other formats
Select “Rich Text Format” and chose a filename
Open the rtf-file in notepad (All files(*.*) -> select file)
What you will see will look nothing like the document, but don’t worry. Press CTRL + F (or click EDIT then FIND) and type “pass” without the quotes and search for it. Above you can see how it looked in my document.
Delete the entire phrase including the waved brackets {}. Make sure to delete only one closing bracket per opening bracket. Otherwise you will get an error when opening it again. It my case it was only the password phrase, but you can also look for “readonly” and “writereservation” and remove these as well.
Save the file
Open the rtf-file in Word again. It will look exactly the same as before.
Activate the Developer section in the ribbon and click “Protect Document” -> Restrict Formatting and Editing
On the bottom of the sidebar that opens click the “Stop Protection” button. You will not be prompted for a password, because we removed it. Now the edit protection is also removed. You can close the sidebar.