To replace the key fob battery in a 2018 Honda Accord, follow these detailed steps.

Gather Necessary Tools

• • A small flathead screwdriver
  • A replacement battery (CR2032)
  • A clean, dry towel or cloth

Open the Key Fob

1. • Begin by flipping the key fob to its backside. You'll notice a small button or switch that releases the physical key from the fob. Press this button and pull out the key.
2. • With the physical key removed, you’ll see a small slot or seam along the edge of the key fob. Use the small flathead screwdriver and insert it into the slot.
   • Gently twist the screwdriver to pry open the key fob casing. Work around the seam carefully to avoid damaging the casing. The two halves should separate easily.

Remove the Old Battery

1. • Once you have opened the casing, you’ll see the battery secured in its compartment. Note the orientation of the battery. It’s typically with the positive side facing up, but ensure you remember or take note of it.
2. • Using the screwdriver or your thumbnail, gently lift and remove the old battery from the compartment.

Insert the New Battery

1. • Take the replacement CR2032 battery and align it in the same orientation as the old battery. Usually, the positive side should be facing upwards.
2. • Press the new battery into the compartment until it’s firmly in place.

Reassemble the Key Fob

1. • Align the two halves of the key fob casing and press them together until they snap securely back into place.
2. • Reinsert the physical key back into its slot.

Test the Key Fob

1. • With the new battery installed and the key fob reassembled, you should test the key fob to ensure it's working correctly. Stand near your vehicle and press any button on the fob to check if it functions properly, such as unlocking or locking the doors.

The process of replacing the key fob battery is relatively simple and can save you time and money compared to visiting a dealership. Always remember to handle the battery with care and dispose of the old battery properly as per local regulations.