Some companies, especially the larger national companies, will use alarm panels which are proprietary, which means only that company can change the programming. If it is not a proprietary panel, the panel can be defaulted and any technician should be able to reprogram it for local alarm only (not monitored).
Best case scenario: You pay a one time labor fee to a professional licensed security technician to reprogram your existing alarm panel. This would probably cost between $69 and $129 per hour depending on your area and the security company rates (estimate only). It should not take more than 1 hour.
Worst case scenario: If the panel is locked to programming you may have to replace the panel and keypads in order to reprogram the alarm. You would pay the cost of equipment as well as labor.
Either way, I recommend that you call a licensed security technician. While you don't need monthly monitoring in order to have a local alarm, it sounds like you will need the advice of a professional technician to get your alarm up and running.
We are a security alarm company in Fort Worth, TX called Lone Star Wiring & Alarm. www.lonestarwa.com.