If you have activated the maximum number of devices which your account is allowed to register, disabling a device will allow you to change which devices are active. To disable a device, select the row of the device and click Disable. You will be prompted to confirm that the device must be disabled. You will receive confirmation that the device was disabled successfully, and the date and time in the Last Disabled column will be updated. Following this action, a device license will be freed up and a new device will be able to connect.
Be aware that once a device is disabled, that same device cannot be activated again for 48 hours. So, please make sure that you are disabling the correct device.