Appending or Linking

Append ( SHIFT+F1) or Link ( Ctrl+Alt+O ) and browse to the ASF_DeskLamp.blend and then go to Group and choose the ASF_DeskLamp group. 

If linked before posing you have to make the armature proxy. With the group selected press CTRL+ALT+P and choose the ASF_DeskL_Armature as proxy.

Posing 

Select the ASF_DeskL_Armature and CTRL+Tab into pose mode.

The control bones are:

Main Bone - use it to position the lamp in the scene

CTRL_LampIK - use it to move the lamp arms around

CTRL_HeadRotation - use it to rotate the head

Chord Bones - use them to position the cable

Power switch bone - this bone allows you to turn on and off the light and set up the temperature.

Use the Z scale to set the intensity of the lamp:

• Turn off -- set to 0 
• Turn on --> set to 1 and above to increase the intensity

Use the Z rotation to set the temperature. A bulb range temperature is between 3800 and 6500, even higher if it's a LED lamp.