Hey guys I’m looking at selling my iPhone X and am wondering how to backup and erase my iPhone through iTunes without updating it. I have 2 people wanting to buy it but they both want me to keep it on iOS 11.3.1 so whoever buys it is gonna want it to stay on that, I just want to save all my info to the computer, then restore the iPhone to factory settings on iOS 11.3.1. It is already jailbroken if that matters.