Most likely, it's in a compartment in the back of the trunk opposite from the driver's side. IMO, use as close as possible to the OEM type of battery. Most good auto parts stores will have a very good match.
Thanks its done. Used a little common sense. I hooked a battery to the jumper posts in the engine compartment. This made the car think it was still attached to the battery. I replaced the battery by only disconnecting cables at the posts. All is perfect now. No resets to deal with .