I am sorry no one has answered you but your post is very vague and unclear. How old is the baby? How many times is it being hand fed per day? Does it have all it's feathers in? Size is not an indicator of being ready to wean. Do you know how to hand feed? Have you done it before?
When you bought it what did the breeder or place you bought it say it was eating? Weaning is a very critical time for any baby bird and has to be carefully monitored. All sorts of soft foods, warm brown rice, fruits and veggies must be offered, you need to know for sure that the bird is successfully eating on it's own before stopping with hand feeding.
Is the baby regurgitating it's food as it says in your post line? If so this can be very serious!!! We really need more information to even begin to start helping you with your questions.