Download Macos Sierra 1012 Dmg File Install Repack -

Choose the USB drive from the boot menu.

Once the "Install macOS Sierra" app is in your Applications folder, you can create a bootable USB drive for a clean installation. A USB flash drive with at least 16GB of space. The drive will be erased, so back up any existing data. The Process: Connect your USB drive to the Mac. download macos sierra 1012 dmg file install

This will download a file named InstallMacOSX.dmg . Extract the Installer: Open the DMG file. Run the .pkg installer found inside. Choose the USB drive from the boot menu