Jardine parrot advice, he's 3 years old?

I just recently purchased a Jardine parrot who is 3 years old from a pet store. They let me put him on layaway so I could take a couple of weeks to let him get more comfortable with me. He chose to let me touch him, which is why I chose him, see, he's a difficult bird and bites when he doesn't like someone. The description they used for him at the store was "social, but selective on who he likes". Now here's my question: does anyone have any experience with this type of bird that could tell me if he's actually going to soften up, or is he going to be a biter for the rest of his life? They told me once he's in a home environment his mood would change drastically. Right now I can't even get him out of his cage without getting nipped or bitten; he's too nervous :S I've never had a bird before so I'm so lost right now!