Just was reading up on my new card and noticed how it said using the 2nd or 3rd BIOs can increase performance, so I'm basically just wanting a run through of how this works and how to do it. 

Yup, higher power target. There is a switch on the side of the PCB that you can use to select the BIOS.

Kobk420
I assume the power needs to be completely off before switching the BIOs? Will this increase performance if running the card stock or only if overclocking? I emailed one of you guys about the BIOs update that ChrisB was talking about in a thread.. I assume that's probably necessary for good results. 

Depend of BIOS. If you flash with BIOS with higher default clock than you will see performance increase without overclocking, on some cards other BIOS only give you more power target and space for overclocking and little more voltages and than performance stay same if you don't overclock. And depend of boost if your card boost on 1150MHz and you flash with BIOS where boost is disable and clock is less than 1150MHz than performance will be smaller without overclocking.

Kobk420
I assume the power needs to be completely off before switching the BIOs? Will this increase performance if running the card stock or only if overclocking? I emailed one of you guys about the BIOs update that ChrisB was talking about in a thread.. I assume that's probably necessary for good results. 

 
Yes, turn off PC before flipping the switch.

Read the instructions.   Every single bios that you can download,  that is trusted,  gives you exact instructions on what to do.   If you get the one from Skynet,  follow those instructions.   If you get the one from Dbianchi, follow his instructions.   Use the search function in the 700 series forum,  and you will find at least two threads containing custom BIOS and if you don't want custom,  use the one the Chris emails you.   It too,  will come with instructions.  Follow them. 

So I flipped the switch running stock and now there's a red light, what's the difference? 
 
Okay so I decided to test it out and ran Shadow Warrior at 1080p and the clock went above the stock boost clock and hit 1163 MHz (didn't check the memory). So I'm guessing it's just a preset BIOs, is there a chance it upped the voltage though? I'm not sure what the default voltage for this card is but I'm going to go check because I'm pretty sure it would hit these speeds stock. 
 
Also when playing the game the card didn't go over 60 C with the fans set to auto and running at a maximum of 45%. Is that good?