If your key is simalar to mine, the two halves are sealed on its edges with some sort of glue. This seal needs to be broken. I used a sharp knive to cut deep all around and then used a screw driver with small hammer to pry open. Be carefull with spring, button and flick key, paying attention to see which way around this is suituated. On reinstalling this I just snap clipped the two sides to gether.

Parry