Recently I needed to print a PDF file that I created a while ago. It happens that I put some stupid printing restriction and I couldn’t remember the password. After doing some research, I found that I didn’t need to pay for expensive software to override the password. This is what I did with ghostscript:
gs -sDEVICE=pdfwrite -sPAPERSIZE=a4 -sOutputFile=fileWithoutPassword.pdf -dNOPAUSE -dBATCH fileWithPassword.pdf
voila!
change according your needs…