Weaning him off really wont work. If you give him any people food, he will hold out from his kibble because he knows he's going to get something better.
If his diet is 20% people food, he MUST be supplemented to insure proper vitamins and minerals, as well as calcium-phosphorus ratio.
My advice to you is pick a good, high-quality kibble and feed it to him
He may hold out for a few meals, but when he realizes he isn't going to get anything better, he'll eat.
How old is he and what does he weigh?