Before You Begin

Before purchasing your lock, check to see whether you have a right- or left-handed door (right-handed doors have hinges on the outside right) and whether it opens into or out of the room. Also measure your door's thickness. This information will help you choose the right lock and determine the proper size drill bits and hole saw size to use for installation.

How to Replace a Door Lock/Knob Assembly

Typical Tools and Materials List:

• Wood chisel (3/4-inch)
• Hammer
• Phillips-head screwdriver
• Utility knife
• Lockset

These instructions provide the basics for replacing a lockset assembly. Different locksets require different final assembly steps, however, so always consult the manufacturer's instructions.

1. Remove the old lock. Some locksets have screws which run through from the inside face of the assembly. Others, however, do not. If you are having trouble figuring out how to remove your door knob, look closely around the stem of the knob. Often there will be a spring-mounted tab there. Pushing in on this tab allows the door knob to slip over it. Once the door knob has been slipped off, you'll have access to the screws that support the entire assembly.
2. The knob hole should be 2-1/8 inches in diameter. If your new lockset won't quite fit in the hole, use a file increase the size as necessary.
3. Trial fit the latch. If it doesn't fit, mark around the latch plate, remove the latch and recess the area inside the marks with a sharp chisel. In a few cases it may also be necessary to enlarge the hole through which the latch passes. You can do this with a spade or forstner bit in a drill, or simply use your chisel. When you're finished, the latch plate should fit flush with the edge of the door.
4. Reinsert the latch and tighten the screws.
5. Replace the strike plate on the door jamb. As with the latch plate, use a chisel to fit the plate if necessary.
6. Put in the exterior knob in place (that's the one with the key hole -- or, for interior locksets, it may be plain or have a small hole in the center of the knob). Run it through (or attach it to)the latch according to the manufacturer's directions.
7. At this point, the directions for installing different locksets can vary depending on the model chosen. You may be able to simply attach the interior knob by fitting it on the spindle and securing the entire assembly with screws. Another type of lockset may require that you secure it with an interior faceplate. Then you'll install the rose (the round trim piece), and slide the knob onto the spindle until the tab catches and holds it in place. Follow the illustrated instructions included with the lockset you choose.