[02ztsian]

Look at the tab where the ring goes-you will notice that it has a gap compared to the rest of the fob. Carefully pry them apart and you will see the battery. But before you replace the battery try cleaning it off, and blowing out the dust inside the fob. I have had my fob quit after I bought a new battery and by prying it apart, wiping off the battery and re-assembling found out it worked again.