Once your bootable USB drive is ready, the installation process is straightforward: Shut down the target Mac completely. Plug the bootable USB drive into a high-speed USB port.
Once you have isolated your InstallESD.dmg file, you can build a physical recovery tool using either macOS or a Windows machine. Method A: Using Disk Utility on an Older Mac mac lion os x 10.7 - installesd.dmg download
Apple currently provides Mac OS X 10.7 Lion as a free download for older systems through its official support site. Mac OS X Lion Installer (4.72 GB) . Once your bootable USB drive is ready, the