How do you disable a factory alarm on a 2011 Toyota sienna?

To disable the factory alarm on a 2011 Toyota Sienna, you can unlock the driver's side door using the key or the remote key fob. If the alarm is activated, it should stop once the door is unlocked. If the alarm continues to sound, you can also try starting the engine with the key, which should deactivate the alarm. If issues persist, consult the owner's manual for specific instructions or seek professional assistance.