most of them are actually soldered into the motherboard. every vio i have opend has had the battery in a heat shrink sleeve with 2 wires coming out to the +/- connector.
90% of the time you have to take the whole back off to get to the battery. they do this on purpose so the bios cannot be cleared easily by a thief who could remove the battery to get past the owners password.
if you want to replace a battery which is unlikely as they last for 7-10 years on the vio you have to take it to a shop where they can replace it professionally. you can take the lappy to the same place and they will reset the bios for you at less cost than removing the battery.
So thats my only option? Also there is this 1 time password thing i get when I enter in the bios pw 3 time incorrectly. whats that?