Tank cover? Ya be a-fixin' the straps to the allen bolt that be holdin' in the black side panel directly below the tank and strap buckle. Ye be needin' to lance a hole in the strap fer the bolt, too. Arrr.
Tank Bag? Dem thar D rings aft the side pockets be fer a fancy shoulder belt for the all important 'wench with pocketbook' look. Yer should be havin' that whence yer got yer bag. Arrr.
The instruction say to poke a hole through the strap at an appropriate place. I took a micro torch and burned a small hole so the nylon wouldn't fray. You could take a piece of metal and heat it and poke the hole with the hot metal for the same affect.
The heated metal probe works really well for good holes in nylon. If you find something with a slight taper, you can increase the diameter as needed by pushing the peice further and further into the strap.
Don't know when you guys got yours but mine already had the hole in it.
If this is the one Smitty sold him it has already been on a bike.
He probably has it figured out by now but just remove the allen from the black plastic around the tank and put the allen through the strap and then the strap connects to the tank cover. It already has a crease where I had it strapped so it will probably work good for you in that location.
Rear straps go around the swivel bolt for the tank under the seat.