The two small pull tabs at the bottom of the winsert are designed to make it easier to remove the winsert from the window. Cut two tabs for each winsert, about 1″ x 2 1/2″ each. Staple them to the bottom edge of the frame. Pound the staples flush to the frame with a hammer.
NOTE: We have found that it is difficult to store winserts together without puncturing the film if they have hard plastic pull tabs. Now we use cloth strips or re-enforced tape to make the pull-tabs.