After 3 years, both of my key fob batteries failed. (I guess that I was lucky. I have heard some of the batteries failing in only 9-12 months). The battery in the key fob is a Panasonic CR2032. I went to Walgreen's and purchased a set of two Energizer batteries for $6.99. The replacement steps are very easy (don't go to the dealer): 1. Remove the valet key by pushing on the slide and pulling it straight out. 2. Using a thin-bladed screwdriver or a knife edge, unsnap the key fob by gently prying around all of the edges. 3. One the key fob splits apart, simply pull out the old battery and insert the new one. (Don't worry, unlike some watches, there are no loose parts inside). 4. Handle the new battery around the edges and push it into place using your thumb and index finger (Tip- Use a small piece of paper towel to avoid getting any hand oil on the new battery and angle the battery in towards the silver retaining clips). 5. Align the two halves of the key fob and snap them together. 6. Reinsert your valet key. 7. Test your locks to insure that they are working. You are done (less than 5 minutes)! Here are some photos to illustrate the install.