Put on safety gloves and glasses to protect yourself from sharp glass shards.
Carefully remove all broken glass pieces from the window frame using a putty knife and gloves.
Use a utility knife to scrape away old glazing putty and loosen any remaining glass fragments.
Measure the window opening accurately to cut the replacement glass to the correct size.
Cut the new glass pane slightly larger than the opening, then carefully trim to fit.
Place the glass into the frame and secure it with glazing points at regular intervals.
Apply a bead of glazing putty around the edges of the glass using a putty knife, ensuring a good seal.
Smooth the putty with the knife to create an even finish and remove excess material.
Allow the putty to cure for the time specified on the product instructions.
Sand the dried putty gently to achieve a smooth surface, avoiding damage to the glass.
Paint over the putty and frame if desired to match the window and protect the seal.
Clean up all broken glass, debris, and tools, and dispose of waste safely.