I would google it - I think you can buy DVD unlocking software which has all the unlock codes via remote on them (well they say all but I doubt it). I have never used these. I have only unlocked a DVD with a free code before someone realised the commercial potential of bundling all codes together and selling them.
I would just google using different search terms such as DVD cracks, DVD firmware software, DVD hacks etc. Or ask a friendly TV salesman who does not have an interest in keeping the info from you. I am bored at work so will have a look for you too and see what I can find.
However, as what you are attempting to do is possibly illegal, or at the very least frowned upon I doubt you will have any comeback if you break your equipment. Or, if you buy something and it does not do the job.
Hope this helps
Graham