How do I start modding this game?

[Tomatketchup]

I want to start modding Farming Simulator 2013 (because I just realized I just drive through citizens, instead of causing hilarious physics mayhem), but I don't know where to start. What programming language? What tools?

[alexbnc]

If you want to add collision on the citizens, you should look for their .i3d files, open them in GIANTS editor (install it from the sdk folder) and you should have some check-box to make the objects rigid bodies. I didn't verified it but I think this would be the way to do it.