Just like SilverLining said, PATIENCE and Positive Reinforcement
When my Benny came home, he was a bit weird about hands/fingers (as most ringnecks are). I just continued to spend a great deal of time with him. I ALWAYS TALK to him Sweetly before I ever try to get close to him.
I NEVER come at him with pointed fingers. The reaction will most certainly be the urge to lunge and bite. Before I pet him, I always show my hand (with fingers held together) telling him sweetly "it's ok". Every chance I get, I talk to him (whether I am physically interacting with him or not). I find that he has improved IMMENSELY from the first day he has come home, just by Talking to him. They are SUPER smart (even at just 3 months old), they respond very positively with sweet baby talk.
Also, I never gave up on him. He is a part of all I do. I have small table top perches I've made that I set up in the kitchen and the bathroom (I also have a suction cup perch in the shower). Once I was able to teach him to step up (which he understood and picked up on quickly, with my talking, calm, patience—now he does it without lunging—he actually gets happy about doing it) I just started carting him around the house with me. When I'm getting ready in the morning in the bathroom, I set him on the perch with big beaded bracelets draped on it (which he loves) in front of the mirror (so he can look at himself and me). He loves being on the perch in the shower too

When I go in the kitchen to clean and cook, he's right there with me, with his perch and large box with toys, food bowl and water. When I do laundry, you guessed it, he's with me on my shoulder.
It takes time and going slowly. Since your baby is still Super Young, you can bond with him quicker than you think. Use repeated phrases, high pitch baby talk and DEFINITELY don't be afraid of him. He just has to learn that you're not trying to hurt him
Like I said, even at such a young age, they are SUPER smart. If you create positive patterns that you do EVERY day, he'll begin to show improvement each day. If you want him to be tame and loving, you have to give him freedom and include him into your daily activities. They LOVE that! Benny's house (I don't like the word 'cage') is ALWAYS open (unless it's night-night time or I have to go somewhere). When I leave the house, I put on a youtube video that has an hd pic of the Amazon rainforest and hours of Amazon sounds (lots of birds and rain), it's very peaceful and seems to keep him happy and relaxed. I also roll his house over to a window
I know that's all a mouthful, but these techniques have made ALL the difference with fully taming my sweet Benny

It didn't take long either. They seem to really like routine (like kids and dogs). When they know what to expect day in and day out, it allows them to feel safe, confident, and more open to be themselves
