This installer is with any Mac that originally shipped with Mac OS X Mountain Lion (10.8) or later. If your Mac is running a very old version like Tiger (10.4) or Leopard (10.5), you must first upgrade to Snow Leopard (10.6) before you can install Lion.
Open the "Install Mac OS X Lion" app from your Applications folder and follow the on-screen instructions. Important Compatibility Note Mac OS X Lion 10.7.5 Free Download
Intel Core 2 Duo, Core i3, Core i5, Core i7, or Xeon. This installer is with any Mac that originally
Open the .pkg file inside the disk image. This will install an app named "Install Mac OS X Lion" into your Applications folder. Mac OS X Lion 10.7.5 Free Download