If you remove the seat, you'll see a nut there over and inside the middle of the battery, that nut lowers the battery tray once you loosen the two nuts to the rear of the battery that fasten it to the frame. Just crank that nut around and the battery will lower down so you can remove it as well as the chrome cover that covers the battery.
Just a suggestion, get a shop manual, they are worth the price any day if you intend to work on your bike.