Storm window is less expensive than new glass windows and can go a long way towards insulating older windows. Many of the older models were made of aluminum, and do not age very well. In addition, they could be deformed or broken, or they may have been poorly sealed or installed years ago. Changing a storm window requires only a few tools and is a suitable project for most of them to do things themselves.
Remove the leaves from the storm windows. They must slide easily out of place. Remove the old window by releasing the screws in the fins that hold the storm window to the window frame. The old layers of paint can make this a bit difficult. Be sure of that you have evaluated the new window correctly. Keep the storm window up to the window opening and make sure that the screw holes are aligned in the wood.
Place a layer of putty on the window frame, where the fins of the storm window will join. Leave the putty without sill. This space is known as drainage holes, and prevent moisture from being trapped on the windowsill and causing decay. Rest the bottom of the storm window along the bottom of the housing and the tip of the window in place.