My ipod touch 4th gen's button is broken

my ipod touch 4th gen's home button is broken and I don't know how to fix it. I'm pretty sure it's stuck, since it only works if I press on it really hard. I'm still under warranty, and I would be willing to get it fixed, but all of my stuff is on here. I've bought all of my music, apps, etc directly from the ipod, and since my laptop is broken i don't even have a way of backing it up. Is there anyway i could just get the button replaced, and not have to replace my ipod? Or is there anyway the apple store will back up my ipod for me?