The magpie ate the meal worms from a sitting position. He tried to pearch on the sticks but it was just too painful for him to use his feet. I mixed up some feed (powdered dog biscuits, wambaroo insectivore mix, 2 boiled eggs, 100g lean minced beef) and force fed him little balls. It was quite a struggle. I'd roll the food into a pea-sized ball, gently force his beak open, then drop the ball into his throat so the swallow reflex would take over. After half a dozen feeds the bird realized "This guy has food!" and actually begged for some. His vocal sounds went from "PISS OFF!" to "feed me pwease." He is still sitting on the floor of the cage but he looks much happier, especially when he sees the food dish.
Now I just have to hope his feet heal enough for him to use them. He's lost 3 claws, fatal for a raptor but not so bad for a magpie.