how do I reset security code for radio

Try calling this number: 800-535-2122

1-800-535-2122 This is the best number... The Person who answered gave me the number... ( FAST )

There was a pass code on radio before I owned it but when I bought it the person who sold it to me forgot the passcode number,how can I get my radio to turn on again.

Mercedes Benz ML500 2002

Before I own it there was a passcode on the radio,the first owner forgot the passcode how can I get my radio to turn on.?

I need the security code for my ML 320 2003 radio