Apple giveback
When I go to trade in my old-iPhone in store, do I need to do a factory reset and /or remove my device from my Apple ID account on it and how will I convert the information from my old phone to my newly purchased one?
When I go to trade in my old-iPhone in store, do I need to do a factory reset and /or remove my device from my Apple ID account on it and how will I convert the information from my old phone to my newly purchased one?
FIrst you back up your old one and use the info to set up your new one
Set up your iPhone, iPad, or iPod touch - Apple Support
Then you wipe your device and remove it from your apple ID
What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support
Personsolly, I keep my phone until I had the new one working perfectly. This may mean two visits to the store or copying over your data in the store.
You do not actually copy your information directly from your old phone to your new. You copy your information from you old phone to iCloud or via iTunes on your computer. You then copy the information from iCloud or via iTunes to your new phone. I'd backup to both places.
What to do before selling or giving away your iPhone, iPad, or iPod touch
http://support.apple.com/kb/ht5661
https://support.apple.com/en-us/HT201351
Apple giveback