Battery dead--trunk won't open..does anyone know if there's a

trunk release anywhere in a 1996 XJS..I bought the car last fall, the battery trickler did not work properly and battery went dead. I can get into the car, but not the trunk--where the battery is! Anybody know what to do? I've tried jump starting the car under the hood, but the keys still won't work in the trunk lock. Thx