the earring you have is internally threaded so you just have to keep turning the ball until it comes out. If not, any piercing place can get it off for you and put the new one on for free.
The only thing I could say about the necklace thing is go out and buy something for her you think she'd like and say the other one was from your brother.
About the earring thing, I haven't got a clue, sorry. You could go to the place you got it and ask.
The ring it just holding it in... At least that's what mine does.