How do I flash my secondary SLI GPU to be the Primary?

880m SLI >> 880m in Alienware 18

the primary 880m electrically shorts out.
the secondary 880m survived, but it wont work in the primary slot, there is error 43 in device manager. It has the bios that sets it to be the secondary.
I have the primary bios already from techpowerup and GPU Z.
But I cannot find flash software that I trust.
What is a trusted software and method to flash my 880m to the other of the two available Dell Bios?

interestingly, the secondary 880m, put in my wonky M18Xr1, in the secondary slot with a nvidia 1000M in the primary, actually works perfectly well, until I reboot and the nvidia software rebels and refuses to load for either card at which point I can actually play DOOM 2016 and it is using the 880m whereas all the other games insist on using the 1000M which is worse than the iGPU for 3d gaming. Doom is showing up NVidia and Dell for being awkward - the card is there, Doom can use it, but Dell and NVidia would rather cover their asses than give us software that makes our hardware work in non standard cases.

Now the 880m is back in the Alienware 18 and it's useless again until I can change its bios. or is there another way around this?

 

https://www.techpowerup.com/download/nvidia-nvflash/


How bout this one? From Dec. 2018.

 

Just swap the secondary to the main slot.

 

It sounds like you are wanting to make the MXM slot 2 a primary slot? If you are just wanting to make the GPU in the MXM slot 2 primary, follow #Rengsey's post

However if you are looking to physically change the physical MXM 2 slot, that may not be possible, but you would need to look at the schematic of the motherboard and see if it is possible with a hardware mod /shrug.