Here's how to reglaze those old broken window panes. First, remove the old glazing compound with a propane torch and putty knife. Carefully remove the old glass and clean the (groove) with a soft wire brush. Apply a thin bead of backglazing, replace the glass, and gently place the push points every eight inches to hold the pane in. Apply a generous bead of fresh glazing compound and smooth it with your putty knife.