Installing a deadbolt lock can be good for your sense of security, and it’s pretty easy to do.
Decide where you want to position the lock and, measuring from the bottom of the door, make a mark on the edge of the door at this height. Use a square to draw a horizontal line on both faces of the door and on the edge.
You should have received instructions and a template with your lock. Using your pencil line as a guide, place this on the door to determine where along your line to drill the hole for the cylinder portion of the lock. Mark this location on both sides of the door. Now, use a hole saw of the size indicated and begin cutting from one side of the door. Stop before you reach the other side; if you pop out the other side, you’ll splinter the face of the door. Instead, cut from the other side so the two holes meet.
Next you need to drill the hole for the bolt. Your template will help you determine the exact location. Use an auger or spade bit of the right size for the bolt. The longer the bit, the easier it will be to drill a straight hole, perfectly perpendicular to the edge of the door.
Once you’ve drilled the hole, insert the bolt in position, and trace the outline of the latch face plate. Use a chisel to create a mortise so the face plate sits flush with the edge of the door. Now insert the bolt, and attach the bolt cylinder and lock as outlined in your instructions. Once you’ve completed the attachment, drill the hole in the jamb and install the strike plate.