you need to remove the door card to get access to the lock which looks tricky with the door locked shut. There's a 'how to' on e36coupe which may help, although its written for a 525 it gives an idea on what needs to be done.
http://www.e36coupe.com/ click 'technical' on left side of home page & see 'how to unlock a deadbolted door'
good luck!