Bios battery change

[inchemapu]

How do I change the date&time battery from a Toshiba NB100? After dissassembling I didn't find any kind of battery inside...
And my computer still send me the same message (change the bios battery)

 

[alexoiu]

https://www.youtube.com/watch?v=8qOboBH_Wbw
Min 11.36