Resetting my parental passcode

Question

I have lost the manual for my Sharp tv, model 19R-M100, and I do not remember the passcode I used many moons ago :) I recently overheard my twin grandsons talking about the 'adult swim' program they had watched the night before but I can't change the parental coverage they have on the tv until I learn how to delete/or reset the passcode. I would appreciate any help you can give me! Thanks a bunch :)