How to Rekey a Lock with a Rekey Kit (Step by Step)
A rekey kit lets you change the internal pins of a lock so it works with a new key instead of the old one. The old key becomes useless, and you keep the existing lock hardware. Here is how the process works.
What Is in a Rekey Kit?
A typical kit includes color-coded bottom pins in multiple sizes (sometimes master pins and springs), a plug follower, a pinning tray, pinning tweezers, a key gauge and tools for removing the cylinder or retaining clip. Kits are usually brand-specific — for example the Kwikset re-keying kit, the DIY Schlage Lock Rekeying Starter Kit, or a padlock-specific kit for Abus, American and Master padlocks.
How to Rekey a Lock: Step by Step
- Remove the cylinder. Take the lock off the door (or remove the knob/lever) using the tools in your kit, then remove the cylinder from the housing.
- Remove the retaining clip or cap at the back of the cylinder.
- Insert the current key and turn it slightly to align the shear line.
- Push the plug out with a plug follower. The follower keeps the top pins and springs in the housing while you slide the plug out. A properly sized plug follower is essential.
- Dump the old bottom pins from the plug.
- Insert the new key into the plug and use a key gauge to read each cut, then load the matching bottom pins from the kit's chart so every pin sits flush with the top of the plug.
- Reinsert the plug, pushing the follower out while keeping the plug and housing together.
- Replace the clip, reassemble and test the new key several times before reinstalling the lock on the door.
Rekeying Kwikset SmartKey Locks
Kwikset SmartKey locks work differently: with the current key inserted and turned, you use the SmartKey learn tool to reset the cylinder, then insert and turn the new key to program it — no disassembly required. The Kwikset Smart Key learn tool is designed for this.
Rekeying Padlocks
Rekeyable padlocks (such as many Abus, American and Master models) follow the same principle: remove the cylinder, replace the pins to match the new key, reassemble and test, using a padlock-specific pinning kit.
Tips for Success
- Work over a tray so springs and pins do not get lost.
- Keep the plug follower tight against the plug when removing it.
- Check each pin is flush with the plug with the new key inserted before reassembly.
Frequently Asked Questions
How does a rekey kit work?
It supplies new pins and the tools to remove a lock's cylinder, replace the old pins with ones that match a new key, and reassemble the lock so the old key no longer works.
Do I need to remove the lock from the door to rekey it?
For standard pin-tumbler locks, yes — the cylinder must come out. Kwikset SmartKey locks can be rekeyed in place with a learn tool.
Can one kit rekey any brand?
Most kits are brand-specific (Kwikset, Schlage, padlocks). Universal kits exist, but you need pins sized for the brand you are working on.