How to Replace a Broken Glass Window Pane

• 1). Measure the length and width of the broken pane and buy a properly sized replacement.
  
  
• 2). Tape the broken glass with masking tape, side-to-side and top-to-bottom. Place two to five strips of tape horizontally and vertically depending on the original size of the pane.
  
  
• 3). Soften the old glazing/putty around the broken pane with a heat gun. Scrape and remove it with a putty knife so that the edges of the glass pane are visible all the way around the pane frame. Remove old push points, if any, and discard.
  
  
• 4). Carefully pull the taped broken pane from the window frame and discard. Wear heavy-duty, leather gloves for this step to avoid injury. (The glass pane should come out nearly all in one piece.)
  
  
• 5). Place the new glass into the pane frame. Insert push points around the edges of the new glass with a putty knife to hold the pane securely in the frame (two pins for each edge).
  
  
• 6). Roll out a four- to five-inch length of glazing/putty material into a small tube. Place the rolled-out tube onto the join between the glass and the pane frame and press into place by hand. Holding a putty knife at about a 45-degree angle, compact the material into the join. Remove excess material from the glass pane and its frame. (You may save the excess material to use on the next edge.) Repeat for the other three edges.