This short video should help: https://www.youtube.com/watch?v=VgTd4--AvLg
Constance, you can go to U tube and watch a tutorial on this installation process. I believe the mechanics involved here may require your husband and/or a helper. Good luck with your project.
Bi-fold doors are sold as kit. ( here is an affiliate shopping link with several choices) That comes with all the necessary hardware and mounting bar. It also comes with directions. Basically you will mount the top runner bar inside the top of the door frame and then click in the bifold door.