title: How to install Xcode from xip file
body: <p>I am very new to macOS, I just need a mac with Xcode to compile my app. However, with macOS Sierra, I have a problem with my USB that is not working anymore (i can't plug my ipad pro)</p>
  
  <p>Under OSX el capitan my usb works great, but now the problem is that app store offer me to download the Xcode 8.3 only that can work only on Sierra (strange they offer you to download something not compatible with your system but doesn't matter, it's apple). so the only way i have is to download manually the xcode 8.2.1</p>
  
  <p>Now my question, how to install the Xcode_8.2.1.xip I just downloaded? and in near future, if I need to update xcode (I guess downloading myself a new version), how will I do? Also where the preferences and configurations settings are saved? does these preferences will be lost on each update?</p>