Demobilizer (i think) issue

[Danc89]

I posted this in the non-performance section before i saw this forum, so here we are again
Ok, so i'm installing these subs on a car i bought a few months ago ('98 cavalier z24) and the car has always had this "shadowguard" alarm system on it, but it hasnt worked. Apparently, when we tried to reconnect the battery after the subs were installed, the alarm decided to go off and start working again, minor issue. My buddy has this "brilliant" idea to just cut the power to the alarm and then voila.... my car is f'ed. Now it won't start, and someone mentioned that the alarm might have a demobilizer or sumthin. Basically, i'd appreciate it if any of you knew how to fix said problem, since my car now wont start, and i cant get anywhere, or listen to my new 12" beauties.

So far we've tried reattaching the wires and letting the alarm go off, but that still doesnt let me start the car, and the remote for the alarm is busted (whadya know).

ps: in case you hadnt figured it out, im no car expert, but i am tech savvy, and found this site, so lay it on me guys