So you have in your possession a DVD which is security protected and you wish to crack this security.
There are a number of ways of cracking this security but I really don't think these methods should be discussed in a forum such as this.
For all we know this DVD may contain the third parties personal details such as bank accounts and passwords.
I appreciate that things may well be exactly as you say but I do not think that it is in the best interest of PPRUNE to advise on such security details.
Sorry guys, flame me if you wish, but some of my DVDs and flash drives are password protected for very good reasons. I certainly wouldn't want them falling into someone else's hands.