Hi Lisa here, and I'm going to show you how to restore your iPhone from an iPod back up, So if you already have the phone on and activated and you want to go back to an old back up that you had on iCloud the first thing you have to do is erase your phone. So you are going to go to your settings then you want to scroll down and tap on general.
From there you will scroll down again and you will choose reset and then you are going to choose erase all content and settings. Once you tap on that if you have a pass code it will ask you to enter it and then it will ask you if you are sure you want to erase your phone twice just to be sure.
When that's done the phone will turn off, it will erase everything off your phone and then it will turn on again. At that point it's going to ask you to enter in your iCloud information so that you can access your backup. Once you've done that it will restore all the information on to the phone and your phone will be just like it was when you made that iCloud back up. And that's it, that's how you restore your iPhone from an iCloud backup.