Here is the installation of my Unity Pillar spotlights. This is not for the faint of heart as you have to drill a 1/2 in hole completely through the pillar. The pay off is a wonderful spotlight that is adjustable. I opted for this because the light is adjustable 360 degress vs. those that are just fixed on a bracket.
REMEBER TO MEASURE 2 or 3 times before drilling and use the right template with the kit. You'll need to by the light kit and the install kit both available from the Unity website here:
http://www.unityusa.com/
No going back from this mod by the way...