Hi there.
I'm guessing you got your bios from here forums.evga.com/EVGA-GeForce-GTX-1070-BIOS-Update-v8604500070-m2565056
And that your card has the part number: 08G-P4-6278-KR
As you said the update process is very easy - When you know how to do it at least :D
First I would download either GPU-Z, EVGA Precision X or MSI Afterburner.
Either of those program are able to tell you which bios version version you're running - GPU-Z shows it in the main window, and in both Precision X and Afterburner you have to click on the Info button.
Depending on where you bought your card/how old it is, the bios might already be updated, so please check first :)
The Bios switch is located on the card itself, and is a small switch located near the power-inputs :)
Edit: Can't post links.. :p