BMW Repair: alarm, obc, brother

Question
I have a 1990 735i my brother was trying to set the time on the car and activated the alarm,(anti theft) I don't have a remote to deactivate the alarm, could you tell me how I could deactivate it manually?

Answer
If he set the code function on the OBC next to the radio you need to unplug the OBC. I forget exactly how to remove it. You could also try disconnecting the battery. That system was not very secure so you should not have too much trouble getting around it.
             Kimber