I am not sure how to disable the alarm, but I can tell you how to disarm it
when it goes off.  Simply shut the door(s), lock with the key from the
outside, and unlock.  That should stop the honking and reset the starter
kill.

I made the mistake of locking the doors on a nice day with the windows
rolled down.  Figuring I could just reach in the window and unlock the doors
from the inside.  Big mistake.  As soon as I opened the door the alarm went
off.  The dealership was no help on the phone.  Luckly another person that
owned a Nissan parked right next to me and told me the little trick.

and I can't start my car. Pls let me know when you find a solution.