Combining what I have done in the past, if you know your PDF password, open your computer, and visit some online websites in your browser, you can remove the password from the PDF, but you need to enter the password before doing that.
Like:
https://www.sodapdf.com/unlock-pdf/
Combining what I have done in the past, if you know your PDF password, open your computer, and visit some online websites in your browser, you can remove the password from the PDF, but you need to enter the password before doing that.
Like:
https://www.sodapdf.com/unlock-pdf/
If you want to remove an unknown password from the PDF, it seems that you need the help of professional PDF password remover software. They are mainly used to work for users who forget the password and want to open the PDF.
Like John the Ripper, Hashcat, and others.
https://www.techspot.com/downloads/6970-john-the-ripper.html
https://www.bestpdfpasswordremover.com/how-to-remove-password-from-pdf.html