There are several reasons you may wish to install locking outlet covers in or outside of your home. Locking covers come in a variety of styles. Some have sliding plates that protect the interior of the outlet from curious fingers while others are covered with a plastic shell that you can lock using a small padlock or other device. This second type is good for exterior outlets to prevent people from using your electricity without your permission.
Turn off the power to your home. Shut off power at your breaker or fuse box, typically located in your garage, basement or utility closet.
Remove the existing outlet cover. Remove the screw from the center of the plate and pull off the cover. If it has been painted over or is stuck, use the tip of the screwdriver or a utility knife to loosen it.
Place the new locking plate over the outlet.
Insert the screw into the center of the plate and screw it in to secure it.