I accidentally dropped something on one of my keys and it popped right off. I tried to push it back in but it won't stay, upon further inspection it seems that the plastic notch has broke. I'm not entirely sure though. Is there a way to fix this without spending a lot of money? Does anyone know if this is an easy fix or if I take it to an Apple store they can fix it right away? I'm worried as to how much it will cost.