its at the end of the game,...after you got the good ending go to el nath than through the portal behind zure and his dad (forgot name)
than u end up back in the final dungeon, go in the middle portal, than figgure out the maze (there is a guide for this ? anyway its not so hard) than through the portal at the end, and you end op in an invisible space maze, figgure it out aswell, through the portal.
and than your in a map wich looks like the final dungeon again, go to the back in the portal, and if im correct you,ll be asked a confirmation, click yes and go in. save your file and than transfer it,...
good luck