Replacing a Volkswagen key battery isn't as daunting a task as you might think. Volkswagen has been producing the same keys for years, and they are simple and well-made, which is why they have not changed for so long. With a little bit of elbow grease and a new battery for the remote, you'll be back on the road in no time.
Press the button on the top side of the remote to get the key in the "open" position, with the key extended out, revealing the center groove on the side of the remote fob.
To separate the remote into two pieces, either grip each end of the remote and pull it apart (don't worry, you won't break it), or place a screwdriver in the side of the remote where the blade flips open. Once the screwdriver is inserted, just twist it, and the remote should separate into two pieces.
Place the top piece of the remote to the side, the part with the actual key on it, and get a grip on the lower part of the remote. Position your fingernails between the crack--again, in the slot where the key usually sits when in the "closed" position--and pull the two pieces apart.
Place the half with the circuit board to the side. Do not allow it to get it wet. Remove the old battery from the housing on the other half of the remote. You can try slapping it into your palm or use a screwdriver to pry it out.
Add the new battery, and reverse the steps to reassemble the remoter. Before sliding on the top part of the remote (the part with the switchblade key on it), click on the buttons to make sure the battery is working. You should see a red light come on if it is working.
