How do you get to the battery on 1989 Harley electra glide classic?

Accessing the battery on a 98 FLHTC, remove the trunk from the docking hardware and you will find one screw at the back end (rear fender end) of the seat in the center of the rear fender, remove the screw and slide the seat to the rear until the locking tongue blade under the front of the seat clears the frame tab.

The battery is located under the seat.