Stupid car

I am getting ready to sell my grandma bonneville car. It's the first time it has been cleaned out and vacuumed since I have owned it. I have had a Toyota Camry sitting in my driveway dormant for about 5 months. It had no problems when I parked it, just parked it to put more miles on the bonneville. So I started to fiddle with it. I bought a new battery for the Camry. The stupid theft alarm system won't shut off and I can't get it to start as a result. I worked on it for an hour or so before I called dad to make it all better. He came over and we both worked on it for another couple of hours. After the first hour we wised up and at least disabled the horn, which was great because then we could hear each other swear. Actually dad did pretty good, I was losing it. At any rate-we haven't figured it out yet. GRRRRRRRRRRRR!