How do you disable an alarm system on a '98 grand prix pontiac?

the alarm on my '98 grand prix won't stop going off after i opened my car today to go home. I tried disabling the battery, and i don't have a remote for the car. i've looked for switches and i've checked the fuse box. i can't seem to find how to disable it. the only evidence i found of an alarm was the horn underneath the hood, and underneath the steering wheel there is a box. kind of like a mini motherboard. and i found the wires to the alarm, but i'm afraid to cut them. and i tried pulling them out, but it doesn't work. please, any advice?