How to Replace the Key Fob Battery in a Chevrolet Blazer

1. Press the button on the side of the remote key and pull out the mechanical key.
2. Pry the two halves of the remote key apart with a flat tool near the key slot.
3. Push the old battery and slide it toward the bottom of the remote key, without using a metal object.
4. Insert a new CR2032 or equivalent battery with the positive side facing the back cover.
5. Check that the silicone mat sits correctly with no gaps or wrinkles.
6. Set the remote key button side down on a hard surface and press the other half straight down to close it.
7. Reinsert the key.

• Replace the battery when the DIC displays REPLACE BATTERY IN REMOTE KEY.
• Do not touch the circuitry; static could damage the remote key.
• The battery is not rechargeable.

Source: 2026 Chevrolet Blazer owner's manual, PDF pages 14, 13. Steps are summarized in our own words (AI-assisted, checked against the cited pages 2026-10-18). Other model years can differ; your manual has the final word.