20 - 30 minutos
My wife's battery wouldn't last a day - she hated her iPhone.
I ordered the battery and had it in my mailbox in 2 days! I took it apart following the online directions and managed to reassemble it. I had a bit of a problem getting 2 of the connectors to seat but I was successful and SHE IS Happy.
Be careful. Get as much bright light on your work area. Be persistent. Be patient. Follow the directions - they work.