toyota avensis v reg alarm problem?

Hi, we have a v reg toyota avensis which has been stood about 2 months. went to start the other day and found battery flat. Jump started, vehicle started straight away. Unfortunatly the alarm now goes off all the time. The only remote we have has been smashed for awhile now, we have been locking using key. Is there a manual way off of disarming alarm so we can use car again without remote?