Note: As of LU48 the access quest is no longer required to enter, though may still be needed for certain quest updates.
There is no zone re-entry. You can enter and exit the foyer up to the time the eyes are placed in the peacock feather sockets but once any of the eyes are placed you cannot re-enter without recollecting the eyes.
Touching the water (the green glowing liquid) anywhere in the zone will spawn heroic mobs (usually level 61^^^).
Respawn on trash mobs is fairly short, about 15 in-game minutes.
Upon entering the zone, open the door to the foyer and enter.
Proceed west (left from the entrance), around the outside of the temple and clear the trash mobs through to roughly the middle-left of the room.
Kill Eshara and Lladan Promanari repeatedly until their final versions spawn. (Note: There are three other Epic x2 named mobs that respawn like Eshara and have a final form like Eshara the Risen. All five will give AA XP as do their revived forms)