2003 Chevy Avalanche Automatic door lock key ring accessory

I dont know of any way except using the scanner the dealership has to add or reprogram new or existing key fobs. Unless you know someone who owns their own Tech2 (GM Dealerships' scanners).

BTW, most dealerships have become more "customer oriented" and I would bet that some would program the remotes on the service drive for no charge. I know the one I work at will if you have bought the remote there.