If you want to reset a PDF file password, the method requires knowledge of the existing password. If you know it, you can open the PDF, remove the current security and save a new copy with a different password.

For removing the existing password without Adobe Acrobat, Softaken PDF Password Recovery can be considered. It requires the current PDF password and can create an unlocked copy of the document, which can then be secured again with a new password if needed.

The important limitation is that this tool does not recover or bypass a forgotten PDF password. So, if the original password is unavailable, checking saved passwords, previous copies or the document owner is the better starting point.