The side panel has a single post sort of in the middle - it is "C"-shaped in cross section.
Just put a 7/32" drill bit in your drill, and eye-ball the mid-point of that post, careful to control the bit from walking -- and drill the hole.
I took two long wire ties, put them together to to make one extra long tie, ran the thin end through the drilled hole, put the cover up close to the bike, connected the other two ends around the frame behind the cover, and finish putting on the cover. Done.
Ever after, for most activities at least, just remove the cover, and let it hang from the wire ties. Only once have I needed to remove the ties completely.