Who I have the same questioned this topic

Sure hope someone can help because getting through to Verizon has proven next to impossible. Online, I ordered a new phone (S20) as a trade-in to replace an older one (S7) on our account. When the S20 arrives, I actually want to give my S10 to the person who had the S7. I understand we can "switch" online, but in what order should I do things? Should we switch BEFORE I activate the S20 or should I activate the S20 for the S7 user and then make the switch? Does this make sense? I feel if I activate the S20 and then make the switch I'll be spending a lot of time transferring S7 stuff to the new S20, just then transfer the S20 stuff to the S10 and vice-versa. Another question is, how does everything actually get transferred? Should I be putting stuff on my computer so I don't lose it? Any advice would be greatly appreciate.