Turn the grill cover inside out. Most covers are manufactured in a specific shape and size to surround the grill when lowered from the top.
Lay the cover on the ground with the torn or ripped area facing up.
Smooth out the area around the rip and push the torn edges together.
Cut a length of duct tape slightly longer than the rip and apply the tape along the length of the damaged area to cover the damage. Smooth out the tape and press tightly to form a strong bond with the plastic cover.
Reverse the cover and replace on the grill.