Remove the mechanical key by pressing the release button and pulling the key out
Locate the seam around the key fob case
Insert a small flathead screwdriver or coin into the seam
Gently twist to separate the two halves
Work around the edge if needed until the fob opens
Replace the battery or inspect the inside as needed
Align the two halves and press them back together until they snap shut
Reinsert the mechanical key if removed