Rekey vs. Replace: What's the Difference?
When you move into a new home, lose a key, or simply want to change who has access, you have two options: replace the entire lock or rekey it. Rekeying means changing the internal pin configuration so old keys no longer work — without replacing the hardware itself. It's faster, cheaper, and just as secure.
What You'll Need
- A rekey kit matched to your lock brand (most brands like Kwikset, Schlage, and others sell their own kits)
- The current working key for the lock
- A small flathead screwdriver
- The new key you want the lock to operate with
- The follower tool (usually included in the kit)
Important: Rekey kits are brand-specific and sometimes model-specific. Confirm compatibility before purchasing.
Step-by-Step Instructions
Step 1: Remove the Lock from the Door
Insert your current working key and turn it about 90 degrees (to the unlock or "take out" position specified in your brand's instructions). This aligns the plug for removal. Use your follower tool or a small screwdriver to press the retaining clip and pull the cylinder plug out of the lock body.
Step 2: Remove the Old Pins
Turn the plug upside down over a white surface. The driver pins and springs will fall out — keep track of them but set them aside; you'll be replacing them. Use the follower tool (a cylinder-shaped rod from your kit) to push the plug out of the housing without letting the top pins fall into the keyway.
Step 3: Remove the Key Pins with the Current Key
Insert the current key into the plug. The key pins (bottom pins) will rise up slightly. Use the pick tool from your kit to remove them one by one from the bottom of the plug's pin chambers.
Step 4: Install New Key Pins
Insert your new key into the plug. Your rekey kit includes a pin chart that tells you which size key pin corresponds to each cut on the new key. Starting from the front of the keyway (pin #1), insert the correct size key pin into each chamber until it sits flush.
Step 5: Reassemble the Cylinder
Carefully slide the plug back into the lock housing using the follower tool to prevent the top pins from dropping into the plug. Replace the driver pins and springs, then reinstall the retaining clip.
Step 6: Test Before Reinstalling
Before putting the lock back on the door, test the new key in the plug assembly. It should turn smoothly. Test the old key too — it should not turn. Once confirmed, reinstall the lock on the door and test again.
Common Mistakes to Avoid
- Using the wrong kit: Always match the kit to your lock brand and model.
- Losing the springs: Work on a tray or white cloth to catch small parts.
- Wrong pin sizes: Double-check the key cut depth chart included in your kit.
- Skipping the pre-install test: Always test the cylinder before reinstalling on the door.
When DIY Rekeying Isn't Recommended
If your lock is damaged, corroded, or you don't have the current working key, call a locksmith instead. Attempting to rekey a lock without the correct key requires disassembly techniques that can damage the cylinder if done incorrectly.
Cost Comparison
| Method | Approximate Cost | Time |
|---|---|---|
| DIY Rekey Kit | $15–$25 per kit | 20–30 minutes |
| Locksmith Rekey | $20–$50 per lock | 15 minutes (pro) |
| Full Lock Replacement | $40–$200+ per lock | 30–60 minutes |
The Bottom Line
Rekeying a lock yourself is a genuinely practical skill. With a $20 kit and half an hour, you can take back control of who has access to your home — no locksmith required.