how to reset parent lock/password on a Panasonic Projection 52" Tv

Hi there. I am very frustrated in the fact that i tried numerous ways to reset my Panasonic Projection TV. I even tried calling Tech Support and to no prevail that didnt even work. The Model # PT-52LCX16 and it is over 10 years old. It is great condition. However I cant remember my password to unlock it. Please advise. thnks