You can find detailed instructions to reprogram the system in a thread someone posted before:
By the way, I wanted to mention that alarm monitoring isn’t just a way to get money from people. It’s a service that actually helps protect lives and homes. Monitored smoke detectors have saved pets from fires, and police have been called during home invasions when people couldn’t call themselves.
Even if you don’t want the service, in many cases, the discount on homeowners insurance more than covers the cost of monitoring.