1. Unplug all your dead cards, plug in the working card (I used USB riser, seating it could work but with the paperclip it’s going to be hard).
2. Boot your PC, press F11 to access BIOS settings (for me). You need enable that you primarily boot from your IGPU (or videocard). It should be somewhere under Advanced Settings > GPU cards or similar.
3. Turn off your PC. I now connected my monitor cable into the VGA input on my motherboard (so it was not directly plugged into the GPU card)
4. Turn your PC on to ensure that you can boot. If OK, turn off.
5. Unplug your working card, and connect one of your dead cards (Power+riser). Keep the monitor cable connected to the motherboard.
6. Use the 1+8 method. This means you connect pins 1 and 8 on your dead GPU using a paperclip, you bridge the pins so that they touch.
7. Turn on your PC. Post screen should appear. If not, check that paperclip is touching pins 1 and 8 (I gave it a nudge).
8. Once in Windows, open the cmd admin prompt for atiflash. Run atiflash -i and your dead card should appear, but state “fail”.
9. Remove the paperclip, re-run atiflash -i, now you should see BIOS version (I liked to take this extra step).
10. Now reflash as you want using atiflash -f -p 0 xxx.rom.
11. Once finished, turn off your PC and repeat from step 5 for each card.
12. Do not forget to enter BIOS one last time to switch back the primary boot to your PCI Express card before you boot up using your resurrected cards.