How to get an old iPhone ready for saleApple has a list of what to do before you sell, give away, or trade in your old iPhone which is worth a look, and we also cover How to wipe and reset an iPhone. 2) Save your dataBefore you get rid of your old iPhone, make sure all the data is backed up and ready to transfer to your new one. Michael Simon/IDG3) Unpair your Apple WatchIf you have an Apple Watch, you should make sure it’s backed up, unpair it from your old iPhone, and sync it with your new one. Tap Unpair Apple Watch. If you have more than one Apple Watch paired to this iPhone, repeat this process for all of them.