Decrypt PDF document using password
First load the document as described in the corresponding how-to article.
Adjust the properties of TElPDFPasswordSecurityHandler class (referenced by EncryptionHandler property) as needed. You will need to set passwords in order to decrypt the data. Passwords are set using OwnerPassword and UserPassword properties. You can use IsUserPasswordValid() and/or IsOwnerPasswordValid() methods of TElPDFPasswordSecurityHandler class to check, if the provided passwords are valid.
Save and close the document using Close() method.