Clear out the area underneath your desk.
Unpack the keyboard drawer from its box. If it requires assembly, follow the instructions that came with the drawer.
Set the keyboard drawer frame in place against the underside of your desk.
Locate the screw mounting holes in the keyboard drawer frame. Mark the wood behind them by passing the felt pen through the screw holes and making a dot on the wood.
Drill a 1/4-inch-deep hole at each marked point on the underside of your desk. Use a drill bit 1/8-inch narrower than the diameter of the screws that came with your drawer. Once finished, replace the drill bit with a screwdriver bit. Place the drill where you can reach it from under the desk.
Set the drawer frame back in position. Hand turn one screw into each hole you drilled, turning each screw until it will stay in the hole on its own.
Continue to hold the frame with one hand as you reach for your drill with screwdriver bits.
Use the power drill to tighten each screw.
Add the keyboard drawer itself, if your model has the drawer separate from the frame.