Deleting non-appearing cast

"Sabaya" has 5 seasons. Over 40 actors appeared in only one season but they are listed for all the 5 seasons that contain 150 episodes. If I start deleting actors with no Appearance for each episode it is going to take ages. What I suggest is that IMDB delete the cast for all epsidoes then I will add actors for each episode. That will save a lot of time.