I'm kinda going by memory here for a 98 V-6 Camry, the unit is near the tranny pan, so it may not be the same proccess. Do NOT drain until you are sure you have found the fill hole and are able to make sure you are able to open it. You have to fill it with one of those hand pumps since the fluid is going against gravity. After you ensure that you can re-fill, I think both the drain and fill uses a 10mm hex bit (like an Allen wrench, try using that first). Can't help you with where the actuall location of the fill hole though.
Good luck and let us know if it is the same for the 96 4 cyl.