|I guess another question would be WHY do you need to access the BIOS?|
There's a jumper on the motherboard that's used to clear the password & reset the BIOS settings to the defaults. And yes, there is also a battery that can be removed instead of using the jumper. It stands in the upright position rather than laying flat on the board. Did you bother to look? It's near the lower right corner of the board. Do you have the motherboard manual? If not, why not? I was able to find it in less than a minute.
BTW, those systems were garbage: