how do i replace and sync the key for my astra 2000 sxi? took key apart and battery fell out? Is this supposed to be like this? thank you

Derrick, May 2010

Replace/renew battery, make sure immobiliser chip is still in the key (if fitted, I think it should be).
Turn ignition on ( dash lights on, dont start engine), press button on remote, doors should lock then unlock, key should now work as normal.
You may have to press the buttons a few times.

por33, May 2010