How to remove a device from my AdGuard account

You can do it via your personal account

If you have a device you no longer use, or if you want to connect a new device, but have reached the device limit supported by your license, you can remove an old device or upgrade the device limit by clicking Increase device limit in your AdGuard account.
To remove a device, follow these steps:
Open your AdGuard account and go to the AdGuard Ad Blocker tab.
Under Devices, find your old device (or the current device if you’ve reinstalled your OS) and click its name.
Click Remove.
If necessary, you can activate your AdGuard license on the new device.
Downloading AdGuard To install AdGuard, click the file indicated by the arrow Select "Open" and click "OK", then wait for the file to be downloaded. In the opened window, drag the AdGuard icon to the "Applications" folder. Thank you for choosing AdGuard! Select "Open" and click "OK", then wait for the file to be downloaded. In the opened window, click "Install". Thank you for choosing AdGuard!
Install AdGuard on your mobile device