1. Login to your Gixxer account with Google Chrome.
2. Download the ‘Install macOS High Sierra’ file.
3. Format a USB stick and call it GixxerUSB
4. Open up the Terminal by pressing CMD+SPACE and type Terminal.
5. Run the following code
sudo /Volumes/Downloads/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/GixxerUSB
6. You will be prompted for your Administrator password
7. Accept the warning to wipe your USB Flash Drive.
Ready to start.
To continue we need to erase the volume at /Volumes/GixxerUSB.
If you wish to continue type (Y) then press return: Y
Erasing Disk: 0%… 10%… 20%… 30%…100%…
Copying installer files to disk…
Making disk bootable…
Copying boot files…
8. Your USB stick is ready for you to mount the EFI folder.
9. Mount the EFI folder and copy and paste contents from EFI_for_High_Sierra.zip
Now that everything is finished, unmount the EFI folder and store away your USB Flash Drive.