- 1). Place a dropcloth under the old window. Remove the old window pane and frame by scoring around the frame with a utility knife to cut into the caulk. If the old pane is cracked, place masking tape over the pane in an X fashion.
- 2). Wedge a chisel blade into the score line and tap with a rubber mallet to shimmy the frame loose. Repeat around the frame as necessary until the old frame is ready to come out. Pull out the old frame and pane with the help of a friend.
- 3). Scrape the window sill, top and side jambs with a putty knife to get up the old caulking. You want to create a clean, even surface. Wipe linseed oil onto the sill, top and jambs, using a rag. Line all four sides with a bead of window caulk, using a caulking gun.
- 4). Fit the new glass window frame and pane into the cleaned, oiled opening. There should be a 1/16-inch to 1/8-inch gap between the opening and the top and two side jambs. Fill the gaps with wood shims until no daylight shines between the glass window's frame and the opening. Tap the shims in with a rubber mallet.
- 5). Caulk around the interior and exterior of the glass window frame to seal it, using a caulking gun. Wipe away any excess caulk with a cloth. Let it sit for 24 hours.
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