Apply heavy-duty packing tape or duct tape across the cracked glass in a crisscross pattern. This keeps the pane from shattering into hundreds of tiny pieces as you remove it.
Guards your eyes against flying glass fragments and old putty chips.
If you have patience, a utility knife, and a high tolerance for frustration, follow the guides. It works. Just remember: measure twice, cut once (or let the hardware store do it), and wear thick gloves.
