How can I disable car alarm on a 2000 Kia Sephia?

I dont have the remote and it never gave me any problems, until a few weeks ago, I tried turning it on and the alarm went off. I cant figure out how to turn it off and I need my car, for now Im driving my husbands car but we need the Kia so that I can drop off and pick up the kids when school resumes. Pls someone help.|||try to check it out first on auto repair shop....