I've tried it numerous times and just gave up. Inspecting both Fob cases I can't seem to find anything different between the two. They are identical. I'm trying to put the old key in the new fob case. Apparently the slug that came with the case is not an identical match to the original key that came with the car. I did have the slug cut but it would not work in the car, I guess they didn't do a good job. Very frustrating.