In case you forgot or accidentally lost the password of encrypted PDF files then you can decrypt them by using a professional Outlook PST password remover tool. This utility is capable to remove the password from single/multiple PDF files in a single run.
in this regard, I have experienced the MCT PST password remover tool. This tool helped me to remove and set a new password in a few of my PST files. You can try its free demo version to analyze the amazing performance of this software.