Don't forget to make a copy of original BIOS before you start doing anything.Instructions lower down and make sure you read everything here before commencing

If anybody wants the code for the DOS commands (Powershell) to type in to flash your GPU BIOS , here they are.
Took me a bit of time to get them right so I thought I would save you the trouble.
Anyway ,
You need to download this software and put it in a desktop folder you made .....call the folder anything you like .
https://www.techpowerup.com/download/nvidia-nvflash/
Also put your BIOS rom downloads in the same folder.
Open a command prompt in the folder you made and use CMD but it's a lot easier doing it in Powershell ( Press SHIFT and RIGHT CLICK whilst in folder ).
Copy and paste these commands in.
Best to copy them into notepad and save them first .
You can then just copy and paste from the saved notepad file you made straight into POWERSHELL  (the blue screen shown below).

(Wish somebody here would have given me the heads up earlier (would have saved me hours) ).

It is risky and this worked for me and I am sure you will be fine but it's your choice to do it and don't blame me if you brick your GPU.
Remember , I used an EVGA ROM although it was from a different model card it was still an EVGA ROM.

I advise only using bios from the same model card (EVGA to EVGA , MSI to MSI etc.).
PS......I called my ROM evga as you can see below but call it anything you like ( just change evga for what you called it so the app knows what to load )
Leave the rest of the commands the way they are, just copy and paste into powershell.
You will know if it's gone right .
They are in order of execution

.\nvflash64 --protectoff
.\nvflash64 -6 evga.rom
.\nvflash64 --protecton
.\nvflash64 --reboot

PS....Don't forget to make a copy of original BIOS before you start doing anything using gpuz below.
https://www.techpowerup.com/gpuz/
and save it in the same folder renaming it or adding "old" to the end , just in case you need to load old BIOS