Radio Code

Does anyone know of a way to find out the code to a BMW radio.....I have a '93 535i. The previous owner lost the code.

Unfortunately I don't live near any dealer....not even close......and they won't do it over the phone.

Model# CM5901L (Alpine I think)
Part # 90 88 1 600 303
Serial # A20910701Z

Any help is much appreciated.