A stiff putty knife (2-inch is ideal), heat gun or hairdryer (to soften old putty), and fine-grit sandpaper.
You don't always need to remove every bit of putty—only the sections that are loose or crumbling. How professionals repair window putty how to fix cracked window putty
Traditional oil-based glazing compound (like DAP '33') or modern hybrid polymer alternatives . 2. Removing the Old, Cracked Putty A stiff putty knife (2-inch is ideal), heat
Repairing cracked window putty is the definition of "sweat equity." It is messy, manual work that requires patience, but the results are superior to modern alternatives like caulk (which shrinks and pulls away) or replacement windows. manual work that requires patience