Gather a small flathead screwdriver or coin and the correct replacement battery
Locate the seam or release slot on the key fob
Insert the flat tool into the slot and gently twist to open the fob
Separate the two halves of the key fob
Remove the old battery
Note the battery orientation before removing it
Insert the new battery in the same orientation
Snap the key fob halves back together
Test the buttons to confirm the fob works
Dispose of the old battery properly