How to Change Locks on Door

Updated October 16, 2026 · 5 min read

How to change locks on door: replace the lock cylinder or full lock assembly with a compatible unit, then test it with the door open before closing it. If the existing lock works and you only need new keys, rekeying may be another option.

Decide Whether to Replace the Lock or Rekey It

Changing a lock means replacing some or all of its hardware. Rekeying keeps the existing lock but changes which key operates it. The right choice depends on the lock’s condition, whether it works smoothly, and whether you want to keep using the same hardware.

If the lock is damaged, loose, difficult to turn, or the wrong style for the door, replacement may make more sense. If the hardware is in good shape and your main goal is to make old keys stop working, ask about rekeying. A lock change service can help when you want a replacement fitted or need help deciding which option suits the door.

How to Change Locks on Door: Start With the Existing Lock

Before removing anything, open the door and leave it open throughout the job. That way, you can check the latch and key operation without risking a lockout if the new hardware is misaligned.

1. 1. Identify the lock — Look at the door to see whether you are replacing a deadbolt, a knob or lever lock, or both. Check how the lock attaches and where its screws sit. Take a photo of the existing hardware before disassembly so you can refer to its layout.
2. 2. Remove the old hardware — Use the correct screwdriver to remove the interior screws and separate the lock pieces. Keep the parts together, and note how the latch sits in the door edge. Avoid forcing stuck parts; extra pressure can damage the door or the surrounding hardware.
3. 3. Compare the replacement — Check that the replacement’s parts line up with the door’s existing openings and latch position. Compare the old lock with the new one before installing it. If the pieces do not fit or the door needs different preparation, pause rather than widening a hole without knowing what is behind the surface.
4. 4. Install and test — Fit the latch and lock components according to the instructions supplied with the hardware. Tighten the screws firmly without overtightening. With the door still open, test the handle, key, and bolt several times before trying the lock with the door shut.

Check the Door and Replacement Hardware Before Installation

A new lock has to work with the door’s existing cutouts and latch position. Before buying hardware, compare the old lock and the door with the replacement’s instructions. A lock that looks similar may still have parts that do not line up with your door.

Inspect the door edge and frame as well as the lock itself. If the door is warped, the latch does not meet the strike plate, or the existing holes are damaged, the problem may need attention beyond swapping the lock.

• Lock type — Confirm whether you need a deadbolt, a knob or lever lock, or replacement hardware for more than one part of the door.
• Existing openings — Compare the replacement with the holes and screw positions already in the door. Do not assume a new lock will fit just because it has a similar appearance.
• Door movement — Check whether the door closes normally and whether the latch and bolt line up with the frame. Alignment problems can make a correctly installed lock hard to operate.
• Included parts and instructions — Read the hardware instructions before starting. Make sure you understand which pieces go on the inside and outside of the door and how the latch should face.

Test the New Lock Before You Close the Door

A lock that turns while the door is open may still bind when the door meets the frame. First, operate the bolt and handle several times with the door open. Check that the key turns smoothly, the latch retracts, and the bolt extends and retracts fully.

Next, bring the door to the frame without locking it and check whether the latch meets the opening in the strike plate. If the bolt rubs, the key sticks, or the door needs force to close, stop and check the alignment and installation. Do not rely on a lock that does not operate smoothly.

Avoid Common Lock Replacement Problems

Most frustrating installation issues start with a poor fit, misplaced parts, or testing only after the door has been shut. Work slowly and keep track of how the original lock came apart. If anything does not line up, pause and compare the pieces rather than forcing them into place.

Take particular care with the latch orientation and the strike plate. If the door or frame is damaged, or you cannot get the lock to turn freely, a professional can assess whether the issue is the hardware or the door alignment.

Know When to Call for a Lock Change

Consider getting help if the lock is damaged, the new hardware does not fit the existing door openings, or the bolt will not move freely after installation. Help can also make sense when you are unsure whether the door needs a full lock replacement or whether rekeying is enough.

Wichita 24 Hour Locksmith provides mobile service at homes, cars, and businesses, and is open 24 hours a day, 7 days a week, including weekends and holidays. A lock change starts from $95 plus hardware, and we tell you the price before work starts. You can reach our locksmith in Wichita or contact us to discuss the door and the lock you need changed.

Frequently asked questions