Mustache parakeet problems...?

To my surprise my mom brought 2 mustache parakeets from our local pet store. We believe one is a boy and one is a girl but we have not found any way to confirm it. Both are around 6 months old and have been "hand fed" the store. I do not know what they think hand feeding is but one of them is not tame. One has a completely green chest and one has a pink tint on its chest. The bird with the pink tint is not nice. Whenever you go near him he will try to bite you. If you try to put him on your finger he will bite you hard and break skin. The bird almost always makes you bleed when he bites you and doesn't have a reason. The other bird with the completely green chest is fairly nice. It nibbles on you but has never broken any ones skin and made me bleed. She will go on your finger if shes in the mood and is much better than the other bird. I need to know how to tame the one that bites because they can open the door and get out of the cage. I can get the girl in but the boy bites me. It hurts allot sometimes and im getting sick of having 2 new cuts on my hands every day