How to reconnect rear speakers & repair central locking system

Hi mate, first of all, SEC is short for Security, the battery has been disconnected or flat. You have to give the VIN number to toyota to get the security code if it is the original stereo. The back speakers may work once this is done, from the boot, check to see if there's wires connected to the speakers. Do the wires look small and factory like? or are they different sizes and fairly bright colours? It's possible the car had a subwoofer and amp in the back, and took them out leaving the cables for them, as it's not a fun job to take them out. If the car has central locking the rest of the doors should unlock when you use the key in the drivers door, otherwise check the fuse block for the central locking fuse, wether it has central locking or not there is a fuse spot for it, if it doesn't have central locking this spot doesn't have a fuse in it from factory, camry's usually have a button on the inside of the car to lock-unlock if it has central locking aswell. Hope this helps.