my alarm is going off, and I can not disarm it

I recently swapped my heads on my 2000 mustang;

now I do not know what to do.

I tryed pulling the fuse on the alarm unit. i was able to get the starter to turn the motor
but it will not start
as soon as i put the fuse back in the red wire of the alarm; the alarm will go off again and I can not disarm it

Is there any way to reset the alarm.

I went over my wire harness and it looks like all my plugs are in the right spot

Any ADVICE?

also notice the mileage on odometer changed after putting new heads on the car
maybe that tripped the alarm

does anyone know how to reset or disarm an alarm after a head change?

My remote locks/unlocks doors but will not disarm the alarm when I plug in the battery. :(