Find the device in the Item Editor of the Brain Management Console, for example by its BLE MAC address (which will be the item's code in the Item Editor). There should be a gear icon in the rightmost column as shown in the image below, indicating the item can be configured. If the device hasn't been used with this Brain before, it may take some time before the gear appears, especially if many new devices are powered at the same time. In this case it will be necessary to reload the table or reopen the Item Editor at a later time.
Clicking the gear icon will open the settings dialog as shown in the image below. The settings shown will depend on the type of device.
After applying the new configuration, it may take a few minutes for the device to receive the new configuration. Reload the item editor at a later time to check back if the configuration was applied; a warning will be shown if configuration changes are still pending.