Why not just use it as is, you got the other half
of the key, and it don't fit in any other car.

Aside from that, I took the ignition lock all apart,
I don't remember if you could get to the key from
there, but I know the thing will come apart with the
right tools, funny thing is, I haven't got a clue what
tools you'll need, it's been 4 years since I had it apart.