The first part is always to gain the conures trust. You can't train anything until you get that. Once he will step up on your hand he will:
1) stop biting on his own.
2) be easily be trained not to bite. If a bird is bonded to you the method is simple...but that's useless until he bonds and likes to perch on you.
To gain trust with a bird that's not a newborn takes time and patience and treats. I assume you know his favorite treat from your friend you got him from.
I'd recommend putting the cage were you usually relax, by the couch in the tv room or by your computer desk, whatever, where ever you spend a lot of time. It should be an area you relax in so you are relaxed, not nervous, no bad emotions he can feed off of, feel confident not scared and he will too. Talk to him often. Open the door occasionally. give him the option to come out on his own, but don't reach into the cage. Once he's bonded he 'probably' won't care but for now it's his "safe zone".
Occasionally offer treats with your hand, then with your other hand near his feet so he can step on them to get the treat. If he trusted his ex-owner then it should go quick, if they never bonded, it might take a while.
Once he's used to you and want's to be with you all the time...if he still bites just put him on the floor when he tries to bite you. About ten feet away, on the floor, nt a cage or perch or play area. He will realize he is being "shunned" by his "flock" and will walk back and be all sweet and lovey...this usually only takes a few tries. It's getting them to be bonded that will take you more time.
Good luck! I hope you have a quick turnaround.
