How to change part of complex gameobject instantiated from prefab?

I have 2d car complex prefab with all colliders and sprites setted, instantiate object from it and I need to change some child element in the runtime by script (e.g. destroy/change posion of wheel) without losing intergrity. How it can be done?

Something like this?

GameObject TMP = Instantiate(prefab,transform.position,transform.rotation) as GameObject;
TMP.transform.FindChild(“Part1”).position = new vector2(0,0);

This works for me in 3D