How to reformat the blade SSD

I have a 2013 A1419 27" iMac (i5/3.4Ghz) which had a cracked display. I got a replacement in, but it took me a couple of days to realize I had to move the heat sensor that was on the old display. Prior to that I had been trying everything to get it working properly and the fan not spinning up!

One thing I tried was to reformat the Blade SSD attached to the back of the logic board, but now that I know the issue wasn't the drive or the installation of same, I need to format the drive back to "unformatted" which is what its designation was before.

I've tried Disk Utility, Drive Genius and I've looked at Terminal commands, but do not find a command or item that does what I need. I think possible "writing zeros" in Drive Genius might, but not sure, any thoughts?

Thanks,

JoeL

ATL