Shisui did the same thing, he tore out his own eye and gave it to Itachi. Itachi then just plopped it into his bird's eye socket.Apparently, changing eyes in the NV is just like changing shoes in our universe. Also, eyes pop out like gumballs when you swipe at them. (It's not just Madara, Danzo did the same thing to Shisui)
Because Sasuke had actual surgery to put it in and he has no regeneration ability.Why did Sasuke's surgery take long?