How to Install or Replace a Cylindrical Door Lock

budzer May 06, 2026

 A step-by-step guide — from removing the old unit to fitting the new one.

Parts of a Cylindrical Lock (refer to diagram)

Exterior Knob, Interior Knob, Shank, Rose (cover plate), Spring Clip, Cylinder, Rotor, Keyway, Mounting Plate, Latch Assembly, Latch Bolt, Face Plate, Strike Plate, Slot (on interior knob).

Step 1 — Remove the Interior Knob

Most cylindrical locks share a standard design, so the removal process is largely the same across brands.

Look at the Interior Knob — the one typically used to push-button lock the door from inside. Near the base of the knob, you will find a small hole. This is the Spring Clip release point.

  1. Insert the pin tool (usually included with the new lock) into the small hole on the Shank.
  2. While pressing the pin, pull the Interior Knob outward. It will detach from the Cylinder assembly.

Step 2 — Remove the Rose (Cover Plate)

The Rose is the decorative plate that sits flush against the door surface on both sides. It conceals the Mounting Plate underneath.

  1. Screw type: Rotate the Rose anticlockwise to unthread and remove it.
  2. Snap type: Use a flat tool to gently unclip the Rose from its tabs.

Step 3 — Remove the Mounting Plate and Main Unit

The Mounting Plate is what holds the entire cylindrical assembly in position through the door.

  1. Locate the two screws on the Mounting Plate — one at the top and one at the bottom.
  2. Remove both screws completely.
  3. Pull the main unit (the Cylinder, Rotor, and attached knob assembly) out from the opposite side of the door.
  4. If it feels stuck, press the Latch Bolt inward slightly — this releases the tension and lets the unit slide out cleanly.
  5. Remove the latch bolt. But don't throw it away. Check if it's still working properly by pressing the bolt inward. If it goes in and out smoothly, it's still in good condition. Keep it. If it's not working properly, keep it for reference.

Step 4 — Prepare the New Lock Unit

Before installing, disassemble the new lock the same way so you have just the main cylinder unit ready to insert.

  1. Insert the included pin into the release hole on the Shank while pulling the Interior Knob — then release the pin. The knob will separate.
  2. Remove the Rose using whichever method applies (screw, snap, or bolt — same as Step 2).
  3. Unscrew the Mounting Plate.
  4. You now have the bare cylinder unit ready for installation.

Before installing, compare the new latch bolt length with the old one. If they match, use the new one. If they differ, use the old one — provided it's still working. If neither works, get a new bolt that matches the original length.

Step 5 — Install the New Lock

  1. Install the Latch Bolt.
  2. From the exterior side of the door, insert the Cylinder assembly into the door hole. Make sure the Slot on the Shank is correctly oriented — it should face the interior side.
  3. As you insert, gently press the Latch Bolt inward so it clears the door hole and the Face Plate sits flush against the door edge.
  4. From the interior side, hold the main unit in place — no need to grip tightly, just steady enough to keep it aligned.
  5. Slide the Mounting Plate onto the Shank, aligning the two screw holes vertically.
  6. Insert both screws loosely — top first, then bottom — so the plate can still be adjusted.
  7. Check that the unit is horizontally level. Then tighten both screws — firm enough that the assembly does not move, but not so tight that it distorts the door face.
  8. Reattach the Rose (screw it clockwise, snap it in, or insert the side screws depending on type).
  9. Slide the Interior Knob back onto the Shank until it clicks securely into place.

Test the Latch Bolt by turning both knobs and verifying the bolt retracts smoothly. Check that the Latch Bolt aligns with the Strike Plate on the door frame when the door closes.

Installation complete.

You're done!

Time to test your new lock. Lock the door, then try opening it without the key — if you can't get in, great news: the installation worked perfectly.

Now grab your key and try again. Opens smoothly? Then you're officially done.

Congratulations! Your door now locks like it means it.

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