You put in transform.position = Vector3() or you can put a Vector3 into other transform functions such as Translate(). Note below, you could also create a variable for a Vector3 and insert that into any of these places.

So it might say something like:

function Update () {
     //You can say Vector3.up for everyone of these, but for teaching 
     //purposes I wrote it out.

     //Also note you would only use one of these at a time or you would get
     //strange results.


     transform.position = Vector3(0, 1, 0); //places the object one up in world space.

     transform.position += Vector3(0, 1, 0); //more complicated.  moves the object up one meter per frame.

     transform.Translate(Vector3(0,1,0));  //same as above but using translate instead.

     transform.Translate(Vector3(0 , 1, 0) * Time.deltaTime);  // Same as above,
     //but each component of the Vector is multiplied by 1/FPS to create movement 
     //in meters per second.
}

The reference also has several examples of Vector3's to check out.