You should prepare a blank USB Flash Disk with DOS or a booting USB Flash Disk.
You extract the file named “ Upgrade MAC” we attached and you will see 2pcs file on the folder.
Notice: when you upgrade MAC, the power must not be blackout.
Copy “ Upgrade MAC” to your blank USB Flash Disk
Insert the USB Flash Disk to your i3 PC and Start the PC, Press “ F11” continually to enter the following image, Select your USB Flash Disk like “SinDisk Curzer Edge 1.27”, Press “ Enter”
Then operate according to the following steps
Select “ No. 07”
Select “ No. o1”
Select “ No. G”
When you see “ A:\>” on the display, you input “c:” and press “Enter”. Then you will see “ C:\>” , input “F” and press “Enter”.
Wait for a moment, the MAC will upgrade well.