A clean reinstall is best for completely removing a modification to the client, which I highly recommend if they were using an illegal one. He can simply delete it and reinstall manually, but he can also use the Hextech Repair Tool found here and it will do it for him.
I am locking this thread for being on the incorrect board, so if he needs further assistance, please have him post on the Help & Support board.
If you have questions or concerns about this action please visit us in the Moderation Discord here.
https://i.gyazo.com/60dae3aaeeb6bf71919cf40fc9e2213e.gif