How to remove the CMOS battery in presario 2500?

I got a presario 2500 that hangs when booting up at the COMPAQ logo. can%26#039;t access the bios, or change the boot sequence. machine is on and running...wanted to try resetting the CMOS...unless some one knows of another solution to this problem, i%26#039;m all eyes....|||Ok, you will have to open the case, and ground yourself either with a anti-static wrist strap, or just by touching wood. On the motherboard, there will be a little button sized battery. That is your CMOS Battery. It can easily be replaced. Just get another Button Battery.