Google Nest does not sell spare parts, but you could try contacting Support:
1. Go to https://support.google.com/googlenest/gethelp. 2. Select a category/product family, and type in a brief description of the issue, then click "Next". 3. Select your device from the dropdown, click "Other", then click "Next step". 4. Under "Resources", just click "Next step". (Clicking one of the listed links will bring up a Help page.) 5. Under "Contact options", choose to get a phone call or chat with the team, depending on availability in your country.
