Hello and welcome to Just answer,
Sorry in advance, this is probably not what you wanted to hear but, the only way to program the Key fobs for the cobalt is a factory Scan tool, there may be an independant repair facility in your are that might have the scan tool needed but this would be hard to find.
There is no "user" procedure as in the past available for your cobalt.
Any more questions just reply back.
Thank you for the accept, any more questions just reply back.