What's the cost for a Chevy Volt key fob battery replacement?

The Chevy Volt's key fob or transmitter battery can be changed by separating the back and front sides of the fob and removing and replacing the 3-volt battery inside. The 3-volt CR2025's can be purchased from any general retailer for less than 5 dollars a piece and are the same batteries used in watches and small mechanical devices. The official OEM part number for the Volts' key fob battery is #13585728F. Turn over the assembly to locate a small switch at the top of the plastic panel. Depress with finger or a small flathead screwdriver to release the existing key. Remove the back of the fob to reveal a second panel covered by plastic. Peel back the plastic and leverage the panel off with a coin or flathead screwdriver. Pop out the the used CR2025 using the same flathead screwdriver and replace. Repeat steps in reverse order to close the remote.