Locate a core drill bit large enough for power cords to fit through, perhaps an inch in diameter. Place the bit on the desk at the location where you’re planning to drill. Trace around the drill bit with a pencil to mark the location.
Attach the core drill bit to your drill. Line up the drill bit with the pencil mark, press down on the drill’s trigger and push.
Continue to drill until you break through to the bottom of the desk. If the desk is thicker than the drill bit, stop the drill once you reach a depth where the top of the bit is even with the desktop. Position a chisel at an angle and chip away at the wood plug of the hole until it breaks free. Remove the wood plug and continue to drill until the hole is fully formed.