How to Rekey a Lock: A Step-by-Step Guide for Locksmiths

🕒 Estimated Reading Time: 3 minutes

Knowing how to rekey a lock is one of the most valuable skills for any locksmith — and one of the most profitable services you can offer. 🔑 A skilled locksmith can rekey a lock in under 10 minutes. In this complete step-by-step guide, we’ll show you exactly how to rekey a lock like a professional, covering every tool and technique you need.

🤔 What is Rekeying and Why Do Clients Need It?

Rekeying changes the internal pin configuration of a lock so existing keys no longer work. Common reasons clients request rekeying:

🏠 Moving into a new home
🔑 Lost or stolen keys
👋 Employee or tenant turnover
💰 More affordable than replacing the entire lockset

🧰 Tools You Need for Rekeying

Rekeying kit — includes plug follower, pinning tray, and tools
Key decoder (or calipers) — to read the existing key’s cuts
Pin kit — assorted driver and key pins for the lock brand
Pick tools — to remove the plug if no key is available
New key blanks — for the lock brand you’re rekeying

✅ Step 1: Remove the Lock from the Door

Start by removing the lockset from the door:

Remove the door handle or knob (usually 2 screws inside the door)
Slide out the cylinder from the lock body
Keep all small parts organized — use a tray or magnetic mat

💡 Take a photo before disassembly so you remember how it goes back together.

✅ Step 2: Remove the Plug

The plug is the rotating cylinder core that holds the key pins.

Insert the original key and rotate it slightly (usually 90°)
Insert the plug follower behind the plug
Push the plug out — the follower keeps driver pins from falling
Carefully keep the cylinder and follower pressed together

✅ Step 3: Remove the Old Key Pins

With the plug on the pinning tray:

Hold the plug over the tray and remove the original key
Use the pinning tool or tweezers to remove each key pin from the plug
Note the number of pin chambers (usually 5 or 6 for residential locks)

✅ Step 4: Decode and Insert New Pins

Now install new key pins to match the new key:

Use your key decoder or calipers to read the new key’s bitting
Select the matching pin sizes for each position
Insert new key pins into each plug chamber in order
Double-check each pin is fully seated

✅ Step 5: Reassemble and Test

Almost done! Reassemble the lock:

Reinsert the plug into the cylinder using the plug follower
Test with the new key — it should turn smoothly
Test that the old key does NOT work
Reinstall the lock on the door and test again

🎉 Rekeying complete!

💡 Pro Rekeying Tips

Always test the new key BEFORE reinstalling the lock on the door
Keep a well-organized pin kit sorted by brand (Kwikset, Schlage, etc.)
Use a plug follower — never skip this step or you’ll have a mess
Practice on bench locks until you can rekey in under 5 minutes

🔑 Rekeying: Simple, Fast, and Profitable

A professional rekey takes 5–15 minutes and typically charges $25–$75 per lock (plus a service call fee). Master this skill and it becomes one of your most reliable income sources. 🔑