Thanks .. Now to figure out how to get the battery cover off without breaking it. Any suggestion

Use a tiny flat head screw driver, a knife, our your fingernails to pry it apart. The plastic case is in two halves, so just find a place along the seam to pry. The best place to start is when you're viewing the fob from the side with the buttons, just to the right of the key ring hole on the bottom is a tiny gap. The battery is a 3V CR2032 button cell.