On a Sony Vaio PCG GRX 560 motherboard, how do I get to the cmos battery?

I have no power, no lights, no fans no hd spin and would like to try and change the cmos battery and don%26#039;t want to dig or take apart more than I have to, can anyone tell me where it is?|||The cmos battery shouldn%26#039;t stop the computer from booting, it%26#039;ll just boot with default settings each time. If you have a totally dead box check the power supply first. You should always at least get a fan whirring or something.