[SOLVED] HELP: disassembly S-16 speed changing

Thank you for everybody for your answers!
I found out a solution in this video:

As you can see, even George-san (ジョージ), who seems very skilful in Plarail tuning, incurred in the same spring accident (maybe without messing everything inside...).

This is the right disposition on the gears:



In addition, I shut this, to show how the speed change device should appear (below the main gears):



What did I learn from this experience?

• Plarail internal mechanism is simple, clean ad perfect
  
• Open your train putting it in a small transparent plastic box...
  

Hope this would help somebody!

Many thanks to all

daniele