Hello. My name is Mike, and I can suggest a couple of options to solve your problem.
As for obtaiing the part, you will need to get it from your local GM dealership, or you can try to locate one in a salvage yard.
It is fairly easy to replace on your own assuming you have the proper socket to remove the receiver from it's mounting.
If there is anything I have not covered, please let me know.
Mike
ASE Certified Technician
20 years experience, all makes and models.