Sometimes you need to change the battery of your car remote as it fails to open one or the other doors and if it is completely dead.
In order to change the battery you must first open your key. This is best done by placing a sharp edge very near to where the key chain slot is located as shown in the image and twisting. It may need some patience and effort to do this. The car remote in the present case was for a Toyota Corolla 2003, quite a old one but in excellent running conditions. As it has run only in Honolulu there are not many miles on it considering its age.
Once you pry open the key, you can change the battery. You would be needing a CR 2016 battery which is very similar to the CR 2032. The CR battery provides 3V and the appropriate battery for Toyota Corolla 2003 is CR 2016. The CR2032 is too thick to be accommodated although if it does accommodate CR 2032 can be used.