Just heard my voicemail from the Apple Store to come in for battery replacement. They are closed right now but have questions. I know they want Find my iPhone turned off. Do they want me to turn it off in front of them? Voicemail said to know my Apple ID & password. Can I just erase my phone before walking in the store? Average battery changing time? How will I know when they're done? I don't think they hand out loaners.