Enter your password.5. Repeat this step for each user on your document. Your password should look something like this (you can edit this here.): password protect your PDF files, you need to use a password to secure the file. Click on ‛Password Protection” to use this option. When you are done, click ‛Process and Save”. Then open your PDF file and choose the Encrypt option. The password you entered for the other users will be shown here: Password to unlock file: Please check that you are a user whose permissions match your users on this file.