Things You'll Need
The Yale Lock Company manufactures door hardware devices for residential and commercial consumers. Yale deadbolts are commonly used in the home as an auxiliary locking device. They are installed on doors with existing latch sets where they help to improve the security of the door. If you're existing Yale deadbolt is no longer functioning properly or you've lost the keys to the lock, you can choose a new unit to replace the old one. These locks are easy to remove and install and are available in many different designs and finishes to complement any door.
Examine the edge of your door near the deadbolt. You'll see a metal latch plate held in place by a pair of screws. Remove these screws, and take the latch plate off the door and set it aside.
Close the door and check the thumbturn on the interior side of the lock. Yale deadbolts are held in place using two screws installed near this thumbturn. Remove these screws, and pull both halves of the lock away from the door.
Buy a new Yale deadbolt that is the same size as your old one. Yale makes many types of trim for these locks, but they are all installed using the same techniques. If you find a decorative trim option that you prefer over the look of your old lock, don't worry that it won't fit your door. As long as the lock body itself is the same, it will fit the existing holes.
Measure the distance from the edge of your door to the center of the bore hole (the hole where the lock will be installed). It will measure either 2-3/8 or 2-3/4 inches. This dimension is known as the backset.
Remove your lock from the package and look for the locking component. This is the part that contains the bolt and is not connected to any trim. On the bolt you'll see a small push button. Slide this button to adjust the backset for the lock. Sliding it one way will shorten the lock to fit a 2-3/8-inch backset while sliding it the other way will lengthen the bolt to fit a 2-3/4-backset. Choose the one that matches the backset on your door.
Place this locking component into the hole so that the bolt protrudes from the edge of the door. Cover it with the latch plate, and use the screws from the package to fasten the plate in place.
Insert the front of the lock into the exterior side of your door. Slide the cylinder tailpiece so that it fits through the locking component. The word "Yale" should be right-side up above the keyhole.
Line up the thumbturn trim so that the connecting bars are aligned with the slots on the lock. Press the thumbturn trim against the door, and lock it in place using the screws that came with the lock. Test your door to ensure the lock is operating properly, and check all keys to make sure they work.