Purchase a legal copy of Mountain Lion.
upgraded my lion to mountain lion with no problem at all, just followed your guide using unibeast then multibeast... just reinstalled applehd kext... but there is no dvd player and when i launch dvd player apps it gives me this message "There was an initialization error A valid DVD drive could not be found. [-70012]". in lion it's ok dvd is working fine. tried fresh install but it is still the same...