In a support page detailing the final update, Google says users will need to manually download, unzip and install the file. Doing so will allow them to pair Glass with their phone — MyGlass will no longer work, but Bluetooth pairing will stay — as well as take photos and videos, as usual. Those who don’t update the device can continue using it, but mirror apps like Gmail, YouTube and Hangouts will no longer work.
After February 25th, 2020, though, they need install the update or they’ll no longer be able to use Glass if they’re not logged in or get logged out. They can wait until they get kicked out of the system to install the file, but they’ll have to keep in mind that the update will only be available until February 25th, 2022.