You can modify the positions and targets of lights after they have been placed in a scene.
Move a Point Light or Spotlight
Select the light glyph, or select the light in the Lights in Model window.
Select the Position grip.
The Position grip is at the bottom of a spotlight and at the center of a point light.
Drag the grip to the new location and click to place the light.
Note: A spotlight rotates as it moves to maintain its aim at the target. If you want to move both source and target, drag the light glyph itself, not the Position grip.
Change the Orientation of a Light
To change the orientation of a light, right-click the light glyph and choose an option from the shortcut menu:
Rotate--Adjusts the orientation of lights.
Flip--Flips the light to a target in the opposite direction.