Replacing the battery in the key fob for your Volkswagen vehicle is simple. The battery, a 3-volt CR2032, is available from many pharmacies and some department stores. If the key fob stops working, this is the first step in an attempt to fix it. If a new battery does not fix the key fob, a replacement may be required.
Press the button releasing the key from the side of the key fob. With the key fob open, look into the slot where the key sits and find the seam running horizontally across the gap.
Insert a flathead screwdriver into the seam and twist it, forcing apart the top and bottom sections of the key fob. Set the top section aside, then grasp the bottom section on either side and pull the front from the back.
Lay the front section aside, and locate the battery in the rear section. Remove the old battery, discard it and install the new battery into the back half of the key fob.
Snap the bottom and top sections of the key fob back together, and test the function of the key fob with the new battery in place.