I've been finding a way to reinstall OS X (or macOS) on the Macbook Pro 8,1 that I've been using. The Macbook has been wiped out to install only Windows 7, and then wiped out again to install Linux. Now, we're in a situation where we need to restore it to its original OS, namely OS X. How do I accomplish this without accessing another OS X machine? I've searched throughout the Internet, maybe I didn't researched enough but it has been almost a month since, and only found handfuls of tutorial which I can't do since they need that I download the installer first and then extract it. I tried Internet Recovery but it asks for an Apple ID, which I assume is the original since I've made one and used that but its no use.
I have downloaded a
InstallMacOSX.dmg from the apple website. I don't know how I should continue from here.
I've tried using dmg2img, which simply converts the .dmg to another format, I've looked into the file contents and there seems to be no bootable folder, e.g. a
/boot directory or something. I've tried booting it from GRUB but no good, and I heard that I should use
dd to put it on a usb but I've heard that it may render it unusable, (i.e. can't be formatted again) so I'm trying to be cautious in this route.
Downloading another version is quite time extensive, so I'd prefer if I could use the existing
.dmg file I've already have in store. But if there's no choice I'm open to download another installer image.
Thank you very much, please tell me I've got something wrong.