Extract from Toyota Corolla AE112 Remote Central Locking and Alarm manual.
Manual Override
1. Unlock the driver door using the ignition key (horn will sound)
2. Using the ignition key quickly turn the ignition switch from the "ACC" to "ON" position 10 times.
3. Leave the ignition at "OFF" position after the tenth turn and wait for the horn to stop sounding.
If not, repeat again.
Hope that helps