I decided to play with GSM because my car had 3 of them (one had non-working start button)

how to take it apart:
1.remove gear shift knob (use drimel, I don't know how to remove it. I couldn't take apart GSM completely, because I couldn't remove knob)
2.remove screws, done!

GSM is electronic plate with a few small switches for all buttons (including start button) and other components.
If your start button is dead (check resistance pushed/released), you need to buy a switch (about $1) and replace it (solder it)