How do I recycle defective nest thermostats?

[Your_buddy_Mike]

it did last 2 years. it just stopped switching the heat on, even though it said "heating". 

[Jake]

Hey Your_buddy_Mike,

Sorry for the late reply. I wanted to follow up and ensure you are good to go. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further. 

Best regards,
Jake

[Your_buddy_Mike]

How do I recycle defective nest thermostats?