Classic Focus Key Battery Replacement Tutorial?

[McEthan]

First, eject the metal mechanical key; otherwise, you won't be able to open the key shell. So, press the physical button to eject the mechanical key. Turn the key sideways, and at the spot marked by the red arrow (1), gently pry open the key shell by lifting up at (2) along the gap. After separation, the 'head' and 'tail' of the key can be stood up. You can then lift the key cover from the gap on the back of the key. Once opened, you can proceed to replace the battery. Finally, reassemble the key.