How to use sliders created in 3D Max in Unity scripts?

Having banged my head against the screen for a few days, it is clear I need some help. I have a beautify model of a construction crane in 3D Max and it has three sliders (nicely circles in red on the image below) to move the cranes hook and trolley and rotate the crane head. When importing the model into Unity, I get three objects in the hierarchy corresponding to the sliders (Slider01.HeadRotation, ..) - but I am failing is to figure out how to manipulate the values (like moving the slider in 3D Max), so the crane moves from a script in Unity? The goal is a crane operator VR game, sitting up in the cabin and be crane king.



Thank you for reading all the way to the end
Thomas