Cry it out method for a 16 month old?

My son is 16 months old and has been sleeping with me ever since he was born. he has gotton so attached to me that he has major seperation anxiety when im not around or even when i walk out the room....he screams bloody murder. just yesterday i tried having him cry it out during nap time and bed time so he can start learning to sleep on his own and be a little independent. im having a baby in november and i want him to learn before his brother comes. any suggestions would help and is the cry it out method to late to try on a 16 month old??? help please.