This is a rough approximation of a seasonally-removable canopy to cover my backyard pergola.
Install hanger bolts evenly along the two edge beams:
Install grommets in the fabric at corresponding locations to the hanger bolts, and thread them over the hanger bolts:
Secure the fabric/grommets to the hanger bolts with the wing nuts.
Now it's easy to remove the cover during the winter season, and re-install it in the spring.