Hi,
sorry,i don't understand the word "please advise as this file is corrupt".
you can download the files to the root catalogue of one sd card or USB.Then insert the sd card or usb into the unit.The way to flash:Press and hold the power button, do not release, and use a sharp thin sticker to press and hold the RST button for around 10 seconds, then you release the RST button, but still keeps hold the power button, you should heard 3 beep sound, then you release the power button, and short press the power button for once, then check will it goes into a English version recovery menu? Please don't let the power off or do other operation, in case led the android board damaged. Here is a video for your reference.
https://www.youtube.com/watch?v=Vtfwfh0Olu4