Replace the sash lock or lock handle on a Pella casement window: pop off the screen, score the paint along the bottom, top, and side stops, remove the operator handle and cover, carefully pry the stops off the jamb, swap the lock or handle, pull the old jamb nails before reinstalling the stops, and reattach the cover and handle.

Step-by-Step Instructions

1. Prepare the Window for Disassembly

• Pella casement windows hide the sash lock behind wood stops, so the stops have to come off before the lock is accessible.
• Pop the screen off and set it aside.
• Use a sharp razor knife to score the paint along the bottom stop, top stop, and the side stop that covers the locking mechanism — this prevents the paint from peeling off the frame when the stops come loose.
• Open the window so you can work on the stops with the sash out of the way.

2. Remove the Operator Handle and Cover

• Loosen the small set screw on the underside of the operator handle and pull the handle off.
• Score any paint along the operator cover, then carefully pop the cover off.
• This clears the way to lift the bottom stop without binding on the operator.

3. Pry Off the Stops

• Slide a pry bar or scraper under the bottom stop and lift it up gently — the stops are held in with small nails, so go slow.
• Repeat on the top stop, wedging the pry bar between the stop and the frame to loosen it.
• Take extra care with the side stop — it is thinner where it has been mortised out for the lock and can split easily on tall windows.
• When prying from the exterior side, keep the pry bar between the stop and the weatherstrip so you do not damage the seal.

4. Replace the Lock or Handle

• With all three stops removed, the operator and sash locking mechanism are exposed.
• Unscrew the old lock (or just the handle) and install the replacement in the same position.
• Test the lock by hand before reinstalling anything to confirm it operates smoothly.

5. Reinstall the Stops, Cover, and Handle

• Pull the old nails out of the window jamb with pliers or wire cutters — trying to line the stops back up onto existing nails almost never works.
• Press the stops back into the jamb; they should wedge tightly into place without new nails. If a stop is loose, tap it home with a wood block and hammer to avoid marring the trim.
• Snap the operator cover back on and tighten the operator nut.
• Reattach the operator handle and tighten the set screw, replace the screen, and your Pella casement window is ready to use.

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