I've read some threads about activation lock and I was hoping you could could tell me how to properly prep my old 5S for sale so no one has issues with locking, etc. when they buy it. This device is out of contract but AT&T says I must wait the 14 day new device period before they will give me the unlock code. That is 3 days away so I will get that when able. It is running iOS 8. In the past, I've just master reset a phone and erased all data but I am thinking that there may be more involved now due to security. Also, do I leave the sim in it or remove it? Thank you for the help!