Okay, just to confirm, the last 8 digits of your VIN are less than 50164913? If not, this bulletin does not apply to your vehicle (unless someone installed a used module from an affected car).
Programming the module will depend on whether you purchase a new one or a used one. In order to install a new module you will require a Tech2 scan tool, a PC with an RS-232 port and a subscription to
http://www.acdelcotds.com in order to access the software that must be downloaded into the module.
If you install a used module then you will need to do a theft deterrent system relearn. I don't have the exact steps for this but you can subscribe to any one of the following and the steps will be outlined there:
http://www.eautorepair.net (Mitchell1 DIY)
http://www.acdelcotds.com (Same online service manual that GM dealerships use)
http://www.alldatadiy.com (A third choice. Many like it, not my favourite though)
As for the part number, the bulletin states you should use P/N 15259522 (if this in fact applies to your car). You can try searching eBay or
www.car-part.com for your year and model. Keep in mind that you 'may' get one that has the same problem.