How To Unlock Mercedes Key Fob Transducer

I have a 2011 Sprinter. It came with only one key. I bought a used Fob with a bank key. Got the key cut, now I’m trying to find out how to unlock the transponder and get it programed into my van. I reaad a posting that member narkeleptk wrote saying that it is possible to unlock that transponder. I need to know how to contact him. I’m new to this site don’t know my way around.