How to replace your flap (video). David July 11, 2019 03:38 Updated Watch this video for instructions on how to replace your flap. If you need help deciding which replacement flap you need Click Here. Related articles Which replacement flap do i need? Installing your security pack (video). Patio Pet Door Installation Video Installation behind your fixed glass panel (video). How Secure is the Panel? Comments 0 comments Please sign in to leave a comment.