Installation discs for Mac OS X
Installation discs for Mac OS X
You need to download the OS from the mac app store, and then use the installer to make the usb an installation usb. If you don't have a mac to download it on, it's illegal and we're not allowed to help with illegal activities
For your friend's Mac, it requires a replacement drive and a complete OS installation.
A download option exists for them in the Mac app store. You can find instructions on creating a bootable installer here: https://support.apple.com/en-us/HT201372
It’s better to purchase directly rather than risk using potentially damaged OS files.
You pay for a price that isn't available to everyone because it's tied to your Mac ownership.