how can i turn off my 1995 BMW 740 il?

Replace your ignition switch module and reprogram a new key. Should be your first option unless you have to return program your anti theft system/ kill switch. Park the car. Place in neutral and engage your emergency brakes. Disconnect your battery. Have it towed to bmw. Let them check out the diagnosis. Then tow it to your friendly neighborhood mechanic. Buy the parts from auto zone, O'Reilly or meyers. Have him install what ever you can't! With the money you saved; buy all the other parts that are a could be culprit! !!