I just got a tank bra (with no instructions), but assuming the one strap goes around the tank by slipping it over the tank from the front(b/w inner fairing and tank), and the other strap attaches under the tank near the rear????

 

Thats the way it installs. Besure you regularly keep it clean and waxed. I know some who like them, but my experience with them is that they will eventually damage the tank through rubbing.