How do you open the key fob for a vauxhall vectra?
on the key fob, turn the key over so that the buttons are on the
back. there is a small groove near the blade/key end of the fob.
you can prise this open using a small screwdriver or if you're
strong pull the blade/key part outward/away from the fob. the
remaining key fob can then be split in two to get at the battery.
beware that you only have a very short time to replace the battery
or the fob will go out of sync with the car.