This is actually a lot easier than re-pinning a lock without a key, it also helps that I had a new Kwikset locking door knob laying around. Not to mention, it also talks about how to go about re-pinning a different style doorknob. If you have the other style doorknob, it should be pretty easy to figure it out after reading this.
After doing this a few times, this shouldn't take more than 5 minutes to finish, but, again, it helps to have detailed instructions.
Things you'll need:
Kwikset Re-Pinning Kit
Doorknob with lock.
Step 1: Removing the Tumbler
With the part that you would put the key in, there should be a little tab behind the handle, as shown in Pic 3.
Insert the original key into the lock and turn it around a bit (Pic 4), then take the thin end of the removal tool and push the tab in. It's a little difficult to take a picture and do this, but you'll need both hands. As you press in with the tool, eventually you'll find a catch with the key, usually in a line from about 10 to 4 o'clock. if 12 to 6 o'clock is the starting point. (Pics 5 and 6).
Then, pull the handle portion off, invert it and the tumbler should fall out (if you've taken out the key). Everything should look about as it does in Pic 8.
Step 2: Removing the Cylinder and Removing the Original Key's Pins
You'll be using two tools from Pic 3 in the rest of this step. They are the funky-shaped tool at the bottom left (also shown in Pic 1), and the white plastic cylinder just above and to the left of it. This is known as the follower bar.
Use the funky shaped tool to push off the plug clip as in pic 4, and then use the little tooth coming off of the tool to pull it off the rest of the way as in Pic 5. This will save your fingernails a lot of grief.
Now comes the follower bar. It gets its name from the fact that you use the hollowed out end to push the cylinder out of the tumbler without having the top pins or pin springs come flying everywhere. As shown in Pic 6. This is a lot easier and tidier than having to pull everything out.
In Pic 7, you can see how the follower bar holds all the innards in place, while the tumbler is pulled out and is showing its brightly colored pins lined up along the shear line.
If you haven't read my guide on doing this process without having the original key, here's a quick description on the way a lock works: The pin springs, top pins and bottom pins all make up how the lock func. The top pins and bottom pins line up along the "shear line" when a key is inserted, allowing the lock cylinder to spin freely. When the key is aligned and removed, the pin springs push the top and bottom pins down, locking the cylinder in place. By using the follower bar, the pin springs and top pins are held in place without having had to be removed for this process, and the bottom pins are sitting in the cylinder and can easily be switched out.
Step 3: Finding Out the New Key's Pins
The pin gauge is a pretty easy tool to find, it's a piece of sheet metal with numbers and a slot on it. You find out what pin corresponds to a depression in a key by lining up the depression in the slot and finding out how far it goes in before it stops. The one shown below in Pic 1 is a depression stopping at a mark of 5.
As shown in Pic 2, you can then find the corresponding pins that match up with the key. In my kit, they're along the bottom row and numbered 1 through 7.
If you want to, you can record the numbers of the pins down. From what I've seen, most people record the numbers by going from the tip of the key to the shoulder of the key. Or from the back of the tumbler to the front. If you swap them around, it might be difficult to get your key to work.
Pic 4 shows the old keys and old pins, the new key and new pins in order and the cylinder.
Setting out the pins in order is sometimes a good way to keep track of your work, but they are tiny, and can move around easily. A clean workspace tends to help keep from having too many lost pins. It also helps to remove the pins from the bag or box with the included tweezers so you don't get your fingers covered in lock oil and you don't get finger oil/debris in the lock.
Step 4: Reassembling the Cylinder and Tumbler
Once all the pins are in the cylinder, they should rest unevenly without the key in, and evenly across the shear line once you insert the key. Note the differences between Pics 2 and 3.
Now for reinserting the cylinder into the tumbler. Turn the key so it is facing roughly the same direction as you removed it in, the 9 and 3 o'clock one. Pic 4 shows how there's no holes for the top pins to go into. Push the follower bar out, without turning the cylinder too much. You can see how much oil is in the locks based on the splotches on the table in Pic 5.
Then, with the key still in and adding pressure, you can turn it until you feel the click of some of the top pins being pushed back into place. When that is done, you can add the plug clip on the back to hold everything in (Pic 6), make sure that the key spins the cylinder freely. That means that the re-pinning has succeeded!
Congratulations, you're almost done!
Step 5: Reassembling the Lock/Door Knob
The good thing about this type of locking door knob is that you just drop the tumbler into the handle, then put the handle back on the main mechanism, and the whole thing is reassembled.
Congratulations, now that you have another door knob that is keyed to one you have around the shop, you can install another door. Or replace another door knob that's older or of a different design.
Plenty of possibilities. Maybe installing a new room?